ETH Price: $3,094.50 (-4.43%)

Transaction Decoder

Block:
23981027 at Dec-10-2025 08:08:11 AM +UTC
Transaction Fee:
0.00030687798091922 ETH $0.95
Gas Used:
1,799,443 Gas / 0.17054054 Gwei

Emitted Events:

242 FiatTokenProxy.0xddf252ad1be2c89b69c2b068fc378daa952ba7f163c4a11628f55a4df523b3ef( 0xddf252ad1be2c89b69c2b068fc378daa952ba7f163c4a11628f55a4df523b3ef, 0x0000000000000000000000004002cd0d867c862af47275ef3457aad1f2c1967b, 0x000000000000000000000000219251982b59499d182c5f25e66c286df53e926a, 0000000000000000000000000000000000000000000000000000000000002328 )
243 FiatTokenProxy.0xddf252ad1be2c89b69c2b068fc378daa952ba7f163c4a11628f55a4df523b3ef( 0xddf252ad1be2c89b69c2b068fc378daa952ba7f163c4a11628f55a4df523b3ef, 0x0000000000000000000000004002cd0d867c862af47275ef3457aad1f2c1967b, 0x000000000000000000000000e33e7ec97d92986f47001032f587735a65406548, 0000000000000000000000000000000000000000000000000000000000000716 )
244 FiatTokenProxy.0xddf252ad1be2c89b69c2b068fc378daa952ba7f163c4a11628f55a4df523b3ef( 0xddf252ad1be2c89b69c2b068fc378daa952ba7f163c4a11628f55a4df523b3ef, 0x0000000000000000000000004002cd0d867c862af47275ef3457aad1f2c1967b, 0x000000000000000000000000eaa35fa57223991bfb5ae785a6668ab19bd77357, 00000000000000000000000000000000000000000000000000000000000000c8 )
245 FiatTokenProxy.0xddf252ad1be2c89b69c2b068fc378daa952ba7f163c4a11628f55a4df523b3ef( 0xddf252ad1be2c89b69c2b068fc378daa952ba7f163c4a11628f55a4df523b3ef, 0x0000000000000000000000004002cd0d867c862af47275ef3457aad1f2c1967b, 0x00000000000000000000000040b77fbf48a9930d007b180e018e06619cf36a0d, 0000000000000000000000000000000000000000000000000000000000000626 )
246 FiatTokenProxy.0xddf252ad1be2c89b69c2b068fc378daa952ba7f163c4a11628f55a4df523b3ef( 0xddf252ad1be2c89b69c2b068fc378daa952ba7f163c4a11628f55a4df523b3ef, 0x0000000000000000000000004002cd0d867c862af47275ef3457aad1f2c1967b, 0x0000000000000000000000003b1355acc80c807bd9f71a8d621e701e20402298, 0000000000000000000000000000000000000000000000000000000000000bb8 )
247 FiatTokenProxy.0xddf252ad1be2c89b69c2b068fc378daa952ba7f163c4a11628f55a4df523b3ef( 0xddf252ad1be2c89b69c2b068fc378daa952ba7f163c4a11628f55a4df523b3ef, 0x0000000000000000000000004002cd0d867c862af47275ef3457aad1f2c1967b, 0x0000000000000000000000004772687d6d1ca0d08b93421860e70ae20bc9476b, 00000000000000000000000000000000000000000000000000000000000003e8 )
248 FiatTokenProxy.0xddf252ad1be2c89b69c2b068fc378daa952ba7f163c4a11628f55a4df523b3ef( 0xddf252ad1be2c89b69c2b068fc378daa952ba7f163c4a11628f55a4df523b3ef, 0x0000000000000000000000004002cd0d867c862af47275ef3457aad1f2c1967b, 0x0000000000000000000000000a1ccb3f359cb2a3508badba1a8f57a495d67e17, 00000000000000000000000000000000000000000000000000000000000018b5 )
249 FiatTokenProxy.0xddf252ad1be2c89b69c2b068fc378daa952ba7f163c4a11628f55a4df523b3ef( 0xddf252ad1be2c89b69c2b068fc378daa952ba7f163c4a11628f55a4df523b3ef, 0x0000000000000000000000004002cd0d867c862af47275ef3457aad1f2c1967b, 0x00000000000000000000000062dd6716590c452fedd8076fc3eeb7276270b8b2, 0000000000000000000000000000000000000000000000000000000000001db0 )
250 FiatTokenProxy.0xddf252ad1be2c89b69c2b068fc378daa952ba7f163c4a11628f55a4df523b3ef( 0xddf252ad1be2c89b69c2b068fc378daa952ba7f163c4a11628f55a4df523b3ef, 0x0000000000000000000000004002cd0d867c862af47275ef3457aad1f2c1967b, 0x000000000000000000000000e9298c334ffa6590123f0886c011919468162176, 00000000000000000000000000000000000000000000000000000000000007d0 )
251 FiatTokenProxy.0xddf252ad1be2c89b69c2b068fc378daa952ba7f163c4a11628f55a4df523b3ef( 0xddf252ad1be2c89b69c2b068fc378daa952ba7f163c4a11628f55a4df523b3ef, 0x0000000000000000000000004002cd0d867c862af47275ef3457aad1f2c1967b, 0x000000000000000000000000849183d244e631c59bdb382bd07f95f1c353802e, 00000000000000000000000000000000000000000000000000000000000003f2 )
252 FiatTokenProxy.0xddf252ad1be2c89b69c2b068fc378daa952ba7f163c4a11628f55a4df523b3ef( 0xddf252ad1be2c89b69c2b068fc378daa952ba7f163c4a11628f55a4df523b3ef, 0x0000000000000000000000004002cd0d867c862af47275ef3457aad1f2c1967b, 0x00000000000000000000000077c6dd595ef2f9476132dafd2a1b6469ed04a9e0, 0000000000000000000000000000000000000000000000000000000000000065 )
253 TetherToken.Transfer( from=[Receiver] 0x4002cd0d867c862af47275ef3457aad1f2c1967b, to=0x27cAA0F171bC085efC805037F32B47cA356a9c0F, value=1000 )
254 TetherToken.Transfer( from=[Receiver] 0x4002cd0d867c862af47275ef3457aad1f2c1967b, to=0xEe08fb22dA718B22C370bd6a9468b2765f3799EB, value=6000 )
255 TetherToken.Transfer( from=[Receiver] 0x4002cd0d867c862af47275ef3457aad1f2c1967b, to=0x5A5990dE8a15F683C8e3f6096Eab334798E53D2e, value=2500 )
256 TetherToken.Transfer( from=[Receiver] 0x4002cd0d867c862af47275ef3457aad1f2c1967b, to=0x34d4886Deb234e54B7A761353981d8aC9c048a29, value=216 )
257 TetherToken.Transfer( from=[Receiver] 0x4002cd0d867c862af47275ef3457aad1f2c1967b, to=0x243627483039aF3B8BE1753B3590BDF65d051111, value=8380 )
258 TetherToken.Transfer( from=[Receiver] 0x4002cd0d867c862af47275ef3457aad1f2c1967b, to=0xe1C1075f6a72c303229E74958Edb7272656944B8, value=2000 )
259 TetherToken.Transfer( from=[Receiver] 0x4002cd0d867c862af47275ef3457aad1f2c1967b, to=0x30142Bd694A055a589A6D793FD7B10B5eD385582, value=2046 )
260 TetherToken.Transfer( from=[Receiver] 0x4002cd0d867c862af47275ef3457aad1f2c1967b, to=0x7fA5c0691a26BCB0EE1C5Db7630C648ecb8df0bD, value=6250 )
261 TetherToken.Transfer( from=[Receiver] 0x4002cd0d867c862af47275ef3457aad1f2c1967b, to=0xD38553AfB5b6A5c258FdA43F04afdd436cC04207, value=3000 )
262 TetherToken.Transfer( from=[Receiver] 0x4002cd0d867c862af47275ef3457aad1f2c1967b, to=0xf7097dFe67b95cA4fF0A7d4E915Cb61BE7680A6A, value=250 )
263 TetherToken.Transfer( from=[Receiver] 0x4002cd0d867c862af47275ef3457aad1f2c1967b, to=0x1C38afEbA2d16BaE2FA5f2d4742Af22783B99d0f, value=1493 )
264 TetherToken.Transfer( from=[Receiver] 0x4002cd0d867c862af47275ef3457aad1f2c1967b, to=0x961251abfA82fFE1022Cc6B64ee84f10B8e3e4e0, value=316 )
265 TetherToken.Transfer( from=[Receiver] 0x4002cd0d867c862af47275ef3457aad1f2c1967b, to=0x589957b453E9eC2E22c5FE3120f5CB3A8D4Da84D, value=5800 )
266 TetherToken.Transfer( from=[Receiver] 0x4002cd0d867c862af47275ef3457aad1f2c1967b, to=0xBD1fb1e22A1Dd15acebe6B09631318769F393C2A, value=729 )
267 TetherToken.Transfer( from=[Receiver] 0x4002cd0d867c862af47275ef3457aad1f2c1967b, to=0xdefdAF6F79f570B17b35C3878345fe146f0E5A16, value=1000 )
268 TetherToken.Transfer( from=[Receiver] 0x4002cd0d867c862af47275ef3457aad1f2c1967b, to=0x7141Ca7EBB693294B96E9931C90bd4aA9C572752, value=370 )
269 TetherToken.Transfer( from=[Receiver] 0x4002cd0d867c862af47275ef3457aad1f2c1967b, to=0x06EeB3AdF5039cb9F59E83ACb4dD3fEbEFb7650d, value=700 )
270 FetchToken.Transfer( from=[Receiver] 0x4002cd0d867c862af47275ef3457aad1f2c1967b, to=0x2D260BD762827b33ff3705718E88b25431ff8aed, value=55680 )
271 LayerZeroToken.Transfer( from=[Receiver] 0x4002cd0d867c862af47275ef3457aad1f2c1967b, to=0xEBbDDb6123715a0EEE884b7c7fe0c1aba9A397EC, value=8369 )

Account State Difference:

  Address   Before After State Difference Code
0x06EeB3Ad...bEFb7650d
0 Eth
Nonce: 0
0.0000111313281576 Eth
Nonce: 0
0.0000111313281576From: 0 To: 0
0x0a1ccB3f...495D67E17
0 Eth
Nonce: 0
0.000009728184488591 Eth
Nonce: 0
0.000009728184488591From: 0 To: 0
0x1C38afEb...783B99d0f
0 Eth
Nonce: 0
0.0000111313281576 Eth
Nonce: 0
0.0000111313281576From: 0 To: 0
0x21925198...DF53e926A
0 Eth
Nonce: 0
0.000009728184488591 Eth
Nonce: 0
0.000009728184488591From: 0 To: 0
0x24362748...65d051111
0 Eth
Nonce: 0
0.0000111313281576 Eth
Nonce: 0
0.0000111313281576From: 0 To: 0
0x27cAA0F1...A356a9c0F
0 Eth
Nonce: 0
0.0000111313281576 Eth
Nonce: 0
0.0000111313281576From: 0 To: 0
0x2D260BD7...431ff8aed
0 Eth
Nonce: 0
0.0000083484961182 Eth
Nonce: 0
0.0000083484961182From: 0 To: 0
0x30142Bd6...5eD385582
0 Eth
Nonce: 0
0.0000111313281576 Eth
Nonce: 0
0.0000111313281576From: 0 To: 0
0x34d4886D...C9c048a29
0 Eth
Nonce: 0
0.0000111313281576 Eth
Nonce: 0
0.0000111313281576From: 0 To: 0
0x3b1355ac...e20402298 0.000003572630667305 Eth0.000009728184488591 Eth0.000006155553821286
0x40B77fBF...19CF36A0D
0 Eth
Nonce: 0
0.000009728184488591 Eth
Nonce: 0
0.000009728184488591From: 0 To: 0
0x4772687D...20BC9476B
0 Eth
Nonce: 0
0.000009728184488591 Eth
Nonce: 0
0.000009728184488591From: 0 To: 0
(Titan Builder)
16.689605780871715519 Eth16.689620176415715519 Eth0.000014395544
0x589957b4...A8D4Da84D
0 Eth
Nonce: 0
0.0000111313281576 Eth
Nonce: 0
0.0000111313281576From: 0 To: 0
0x5A5990dE...798E53D2e
0 Eth
Nonce: 0
0.0000111313281576 Eth
Nonce: 0
0.0000111313281576From: 0 To: 0
0x6985884C...7F13271cd
0x7141Ca7E...A9C572752
0 Eth
Nonce: 0
0.0000111313281576 Eth
Nonce: 0
0.0000111313281576From: 0 To: 0
0x77C6dD59...9ed04a9e0
0 Eth
Nonce: 0
0.000009728184488591 Eth
Nonce: 0
0.000009728184488591From: 0 To: 0
0x7fA5c069...ecb8df0bD
0 Eth
Nonce: 0
0.0000111313281576 Eth
Nonce: 0
0.0000111313281576From: 0 To: 0
0x849183D2...1C353802E
0 Eth
Nonce: 0
0.000009728184488591 Eth
Nonce: 0
0.000009728184488591From: 0 To: 0
0x961251ab...0B8e3e4e0
0 Eth
Nonce: 0
0.0000111313281576 Eth
Nonce: 0
0.0000111313281576From: 0 To: 0
0xA0b86991...E3606eB48
0xaea46A60...7EF41Ad85
0xB06Eb69E...C2Edb993E
(Fake_Phishing1674516)
0.009423401175991937 Eth
Nonce: 618
0.008846494884363651 Eth
Nonce: 619
0.000576906291628286
0xBD1fb1e2...69F393C2A
0 Eth
Nonce: 0
0.0000111313281576 Eth
Nonce: 0
0.0000111313281576From: 0 To: 0
0xD38553Af...36cC04207
0 Eth
Nonce: 0
0.0000111313281576 Eth
Nonce: 0
0.0000111313281576From: 0 To: 0
0xdAC17F95...13D831ec7
0xdefdAF6F...46f0E5A16
0 Eth
Nonce: 0
0.0000111313281576 Eth
Nonce: 0
0.0000111313281576From: 0 To: 0
0xe33E7ec9...a65406548 0.000008750961778948 Eth0.000009728184488591 Eth0.000000977222709643
0xE9298C33...468162176
0 Eth
Nonce: 0
0.000009728184488591 Eth
Nonce: 0
0.000009728184488591From: 0 To: 0
0xEBbDDb61...ba9A397EC
0 Eth
Nonce: 0
0.0000083484961182 Eth
Nonce: 0
0.0000083484961182From: 0 To: 0
0xEe08fb22...65f3799EB
0 Eth
Nonce: 0
0.0000111313281576 Eth
Nonce: 0
0.0000111313281576From: 0 To: 0
0xf7097dFe...BE7680A6A
0 Eth
Nonce: 0
0.0000111313281576 Eth
Nonce: 0
0.0000111313281576From: 0 To: 0

Execution Trace

ETH 0.000270028310709066 Fake_Phishing1685683.add79277( )
  • FiatTokenProxy.a9059cbb( )
    • FiatTokenV2_2.transfer( to=0x219251982B59499d182c5f25E66c286DF53e926A, value=9000 ) => ( True )
    • FiatTokenProxy.a9059cbb( )
      • FiatTokenV2_2.transfer( to=0xe33E7ec97D92986f47001032F587735a65406548, value=1814 ) => ( True )
      • FiatTokenProxy.a9059cbb( )
        • FiatTokenV2_2.transfer( to=0xEaa35FA57223991Bfb5AE785a6668AB19bD77357, value=200 ) => ( True )
        • FiatTokenProxy.a9059cbb( )
          • FiatTokenV2_2.transfer( to=0x40B77fBF48A9930D007B180E018e06619CF36A0D, value=1574 ) => ( True )
          • FiatTokenProxy.a9059cbb( )
            • FiatTokenV2_2.transfer( to=0x3b1355acc80C807Bd9f71A8d621E701e20402298, value=3000 ) => ( True )
            • FiatTokenProxy.a9059cbb( )
              • FiatTokenV2_2.transfer( to=0x4772687D6D1Ca0D08b93421860E70ae20BC9476B, value=1000 ) => ( True )
              • FiatTokenProxy.a9059cbb( )
                • FiatTokenV2_2.transfer( to=0x0a1ccB3f359CB2a3508bADBa1A8F57A495D67E17, value=6325 ) => ( True )
                • FiatTokenProxy.a9059cbb( )
                  • FiatTokenV2_2.transfer( to=0x62Dd6716590c452FEDd8076fc3eeB7276270B8b2, value=7600 ) => ( True )
                  • FiatTokenProxy.a9059cbb( )
                    • FiatTokenV2_2.transfer( to=0xE9298C334ffA6590123F0886c011919468162176, value=2000 ) => ( True )
                    • FiatTokenProxy.a9059cbb( )
                      • FiatTokenV2_2.transfer( to=0x849183D244e631C59BdB382bD07f95f1C353802E, value=1010 ) => ( True )
                      • FiatTokenProxy.a9059cbb( )
                        • FiatTokenV2_2.transfer( to=0x77C6dD595eF2f9476132dAfD2A1b6469ed04a9e0, value=101 ) => ( True )
                        • TetherToken.transfer( _to=0x27cAA0F171bC085efC805037F32B47cA356a9c0F, _value=1000 )
                        • TetherToken.transfer( _to=0xEe08fb22dA718B22C370bd6a9468b2765f3799EB, _value=6000 )
                        • TetherToken.transfer( _to=0x5A5990dE8a15F683C8e3f6096Eab334798E53D2e, _value=2500 )
                        • TetherToken.transfer( _to=0x34d4886Deb234e54B7A761353981d8aC9c048a29, _value=216 )
                        • TetherToken.transfer( _to=0x243627483039aF3B8BE1753B3590BDF65d051111, _value=8380 )
                        • TetherToken.transfer( _to=0xe1C1075f6a72c303229E74958Edb7272656944B8, _value=2000 )
                        • TetherToken.transfer( _to=0x30142Bd694A055a589A6D793FD7B10B5eD385582, _value=2046 )
                        • TetherToken.transfer( _to=0x7fA5c0691a26BCB0EE1C5Db7630C648ecb8df0bD, _value=6250 )
                        • TetherToken.transfer( _to=0xD38553AfB5b6A5c258FdA43F04afdd436cC04207, _value=3000 )
                        • TetherToken.transfer( _to=0xf7097dFe67b95cA4fF0A7d4E915Cb61BE7680A6A, _value=250 )
                        • TetherToken.transfer( _to=0x1C38afEbA2d16BaE2FA5f2d4742Af22783B99d0f, _value=1493 )
                        • TetherToken.transfer( _to=0x961251abfA82fFE1022Cc6B64ee84f10B8e3e4e0, _value=316 )
                        • TetherToken.transfer( _to=0x589957b453E9eC2E22c5FE3120f5CB3A8D4Da84D, _value=5800 )
                        • TetherToken.transfer( _to=0xBD1fb1e22A1Dd15acebe6B09631318769F393C2A, _value=729 )
                        • TetherToken.transfer( _to=0xdefdAF6F79f570B17b35C3878345fe146f0E5A16, _value=1000 )
                        • TetherToken.transfer( _to=0x7141Ca7EBB693294B96E9931C90bd4aA9C572752, _value=370 )
                        • TetherToken.transfer( _to=0x06EeB3AdF5039cb9F59E83ACb4dD3fEbEFb7650d, _value=700 )
                        • FetchToken.transfer( recipient=0x2D260BD762827b33ff3705718E88b25431ff8aed, amount=55680 ) => ( True )
                        • LayerZeroToken.transfer( to=0xEBbDDb6123715a0EEE884b7c7fe0c1aba9A397EC, value=8369 ) => ( True )
                        • ETH 0.000009728184488591 0x219251982b59499d182c5f25e66c286df53e926a.CALL( )
                        • ETH 0.000000977222709643 0xe33e7ec97d92986f47001032f587735a65406548.CALL( )
                        • ETH 0.000009728184488591 0x40b77fbf48a9930d007b180e018e06619cf36a0d.CALL( )
                        • ETH 0.000006155553821286 0x3b1355acc80c807bd9f71a8d621e701e20402298.CALL( )
                        • ETH 0.000009728184488591 0x4772687d6d1ca0d08b93421860e70ae20bc9476b.CALL( )
                        • ETH 0.000009728184488591 0x0a1ccb3f359cb2a3508badba1a8f57a495d67e17.CALL( )
                        • ETH 0.000009728184488591 0xe9298c334ffa6590123f0886c011919468162176.CALL( )
                        • ETH 0.000009728184488591 0x849183d244e631c59bdb382bd07f95f1c353802e.CALL( )
                        • ETH 0.000009728184488591 0x77c6dd595ef2f9476132dafd2a1b6469ed04a9e0.CALL( )
                        • ETH 0.0000111313281576 0x27caa0f171bc085efc805037f32b47ca356a9c0f.CALL( )
                        • ETH 0.0000111313281576 0xee08fb22da718b22c370bd6a9468b2765f3799eb.CALL( )
                        • ETH 0.0000111313281576 0x5a5990de8a15f683c8e3f6096eab334798e53d2e.CALL( )
                        • ETH 0.0000111313281576 0x34d4886deb234e54b7a761353981d8ac9c048a29.CALL( )
                        • ETH 0.0000111313281576 0x243627483039af3b8be1753b3590bdf65d051111.CALL( )
                        • ETH 0.0000111313281576 0x30142bd694a055a589a6d793fd7b10b5ed385582.CALL( )
                        • ETH 0.0000111313281576 0x7fa5c0691a26bcb0ee1c5db7630c648ecb8df0bd.CALL( )
                        • ETH 0.0000111313281576 0xd38553afb5b6a5c258fda43f04afdd436cc04207.CALL( )
                        • ETH 0.0000111313281576 0xf7097dfe67b95ca4ff0a7d4e915cb61be7680a6a.CALL( )
                        • ETH 0.0000111313281576 0x1c38afeba2d16bae2fa5f2d4742af22783b99d0f.CALL( )
                        • ETH 0.0000111313281576 0x961251abfa82ffe1022cc6b64ee84f10b8e3e4e0.CALL( )
                        • ETH 0.0000111313281576 0x589957b453e9ec2e22c5fe3120f5cb3a8d4da84d.CALL( )
                        • ETH 0.0000111313281576 0xbd1fb1e22a1dd15acebe6b09631318769f393c2a.CALL( )
                        • ETH 0.0000111313281576 0xdefdaf6f79f570b17b35c3878345fe146f0e5a16.CALL( )
                        • ETH 0.0000111313281576 0x7141ca7ebb693294b96e9931c90bd4aa9c572752.CALL( )
                        • ETH 0.0000111313281576 0x06eeb3adf5039cb9f59e83acb4dd3febefb7650d.CALL( )
                        • ETH 0.0000083484961182 0x2d260bd762827b33ff3705718e88b25431ff8aed.CALL( )
                        • ETH 0.0000083484961182 0xebbddb6123715a0eee884b7c7fe0c1aba9a397ec.CALL( )
                          File 1 of 5: FiatTokenProxy
                          pragma solidity ^0.4.24;
                          
                          // File: zos-lib/contracts/upgradeability/Proxy.sol
                          
                          /**
                           * @title Proxy
                           * @dev Implements delegation of calls to other contracts, with proper
                           * forwarding of return values and bubbling of failures.
                           * It defines a fallback function that delegates all calls to the address
                           * returned by the abstract _implementation() internal function.
                           */
                          contract Proxy {
                            /**
                             * @dev Fallback function.
                             * Implemented entirely in `_fallback`.
                             */
                            function () payable external {
                              _fallback();
                            }
                          
                            /**
                             * @return The Address of the implementation.
                             */
                            function _implementation() internal view returns (address);
                          
                            /**
                             * @dev Delegates execution to an implementation contract.
                             * This is a low level function that doesn't return to its internal call site.
                             * It will return to the external caller whatever the implementation returns.
                             * @param implementation Address to delegate.
                             */
                            function _delegate(address implementation) internal {
                              assembly {
                                // Copy msg.data. We take full control of memory in this inline assembly
                                // block because it will not return to Solidity code. We overwrite the
                                // Solidity scratch pad at memory position 0.
                                calldatacopy(0, 0, calldatasize)
                          
                                // Call the implementation.
                                // out and outsize are 0 because we don't know the size yet.
                                let result := delegatecall(gas, implementation, 0, calldatasize, 0, 0)
                          
                                // Copy the returned data.
                                returndatacopy(0, 0, returndatasize)
                          
                                switch result
                                // delegatecall returns 0 on error.
                                case 0 { revert(0, returndatasize) }
                                default { return(0, returndatasize) }
                              }
                            }
                          
                            /**
                             * @dev Function that is run as the first thing in the fallback function.
                             * Can be redefined in derived contracts to add functionality.
                             * Redefinitions must call super._willFallback().
                             */
                            function _willFallback() internal {
                            }
                          
                            /**
                             * @dev fallback implementation.
                             * Extracted to enable manual triggering.
                             */
                            function _fallback() internal {
                              _willFallback();
                              _delegate(_implementation());
                            }
                          }
                          
                          // File: openzeppelin-solidity/contracts/AddressUtils.sol
                          
                          /**
                           * Utility library of inline functions on addresses
                           */
                          library AddressUtils {
                          
                            /**
                             * Returns whether the target address is a contract
                             * @dev This function will return false if invoked during the constructor of a contract,
                             * as the code is not actually created until after the constructor finishes.
                             * @param addr address to check
                             * @return whether the target address is a contract
                             */
                            function isContract(address addr) internal view returns (bool) {
                              uint256 size;
                              // XXX Currently there is no better way to check if there is a contract in an address
                              // than to check the size of the code at that address.
                              // See https://ethereum.stackexchange.com/a/14016/36603
                              // for more details about how this works.
                              // TODO Check this again before the Serenity release, because all addresses will be
                              // contracts then.
                              // solium-disable-next-line security/no-inline-assembly
                              assembly { size := extcodesize(addr) }
                              return size > 0;
                            }
                          
                          }
                          
                          // File: zos-lib/contracts/upgradeability/UpgradeabilityProxy.sol
                          
                          /**
                           * @title UpgradeabilityProxy
                           * @dev This contract implements a proxy that allows to change the
                           * implementation address to which it will delegate.
                           * Such a change is called an implementation upgrade.
                           */
                          contract UpgradeabilityProxy is Proxy {
                            /**
                             * @dev Emitted when the implementation is upgraded.
                             * @param implementation Address of the new implementation.
                             */
                            event Upgraded(address implementation);
                          
                            /**
                             * @dev Storage slot with the address of the current implementation.
                             * This is the keccak-256 hash of "org.zeppelinos.proxy.implementation", and is
                             * validated in the constructor.
                             */
                            bytes32 private constant IMPLEMENTATION_SLOT = 0x7050c9e0f4ca769c69bd3a8ef740bc37934f8e2c036e5a723fd8ee048ed3f8c3;
                          
                            /**
                             * @dev Contract constructor.
                             * @param _implementation Address of the initial implementation.
                             */
                            constructor(address _implementation) public {
                              assert(IMPLEMENTATION_SLOT == keccak256("org.zeppelinos.proxy.implementation"));
                          
                              _setImplementation(_implementation);
                            }
                          
                            /**
                             * @dev Returns the current implementation.
                             * @return Address of the current implementation
                             */
                            function _implementation() internal view returns (address impl) {
                              bytes32 slot = IMPLEMENTATION_SLOT;
                              assembly {
                                impl := sload(slot)
                              }
                            }
                          
                            /**
                             * @dev Upgrades the proxy to a new implementation.
                             * @param newImplementation Address of the new implementation.
                             */
                            function _upgradeTo(address newImplementation) internal {
                              _setImplementation(newImplementation);
                              emit Upgraded(newImplementation);
                            }
                          
                            /**
                             * @dev Sets the implementation address of the proxy.
                             * @param newImplementation Address of the new implementation.
                             */
                            function _setImplementation(address newImplementation) private {
                              require(AddressUtils.isContract(newImplementation), "Cannot set a proxy implementation to a non-contract address");
                          
                              bytes32 slot = IMPLEMENTATION_SLOT;
                          
                              assembly {
                                sstore(slot, newImplementation)
                              }
                            }
                          }
                          
                          // File: zos-lib/contracts/upgradeability/AdminUpgradeabilityProxy.sol
                          
                          /**
                           * @title AdminUpgradeabilityProxy
                           * @dev This contract combines an upgradeability proxy with an authorization
                           * mechanism for administrative tasks.
                           * All external functions in this contract must be guarded by the
                           * `ifAdmin` modifier. See ethereum/solidity#3864 for a Solidity
                           * feature proposal that would enable this to be done automatically.
                           */
                          contract AdminUpgradeabilityProxy is UpgradeabilityProxy {
                            /**
                             * @dev Emitted when the administration has been transferred.
                             * @param previousAdmin Address of the previous admin.
                             * @param newAdmin Address of the new admin.
                             */
                            event AdminChanged(address previousAdmin, address newAdmin);
                          
                            /**
                             * @dev Storage slot with the admin of the contract.
                             * This is the keccak-256 hash of "org.zeppelinos.proxy.admin", and is
                             * validated in the constructor.
                             */
                            bytes32 private constant ADMIN_SLOT = 0x10d6a54a4754c8869d6886b5f5d7fbfa5b4522237ea5c60d11bc4e7a1ff9390b;
                          
                            /**
                             * @dev Modifier to check whether the `msg.sender` is the admin.
                             * If it is, it will run the function. Otherwise, it will delegate the call
                             * to the implementation.
                             */
                            modifier ifAdmin() {
                              if (msg.sender == _admin()) {
                                _;
                              } else {
                                _fallback();
                              }
                            }
                          
                            /**
                             * Contract constructor.
                             * It sets the `msg.sender` as the proxy administrator.
                             * @param _implementation address of the initial implementation.
                             */
                            constructor(address _implementation) UpgradeabilityProxy(_implementation) public {
                              assert(ADMIN_SLOT == keccak256("org.zeppelinos.proxy.admin"));
                          
                              _setAdmin(msg.sender);
                            }
                          
                            /**
                             * @return The address of the proxy admin.
                             */
                            function admin() external view ifAdmin returns (address) {
                              return _admin();
                            }
                          
                            /**
                             * @return The address of the implementation.
                             */
                            function implementation() external view ifAdmin returns (address) {
                              return _implementation();
                            }
                          
                            /**
                             * @dev Changes the admin of the proxy.
                             * Only the current admin can call this function.
                             * @param newAdmin Address to transfer proxy administration to.
                             */
                            function changeAdmin(address newAdmin) external ifAdmin {
                              require(newAdmin != address(0), "Cannot change the admin of a proxy to the zero address");
                              emit AdminChanged(_admin(), newAdmin);
                              _setAdmin(newAdmin);
                            }
                          
                            /**
                             * @dev Upgrade the backing implementation of the proxy.
                             * Only the admin can call this function.
                             * @param newImplementation Address of the new implementation.
                             */
                            function upgradeTo(address newImplementation) external ifAdmin {
                              _upgradeTo(newImplementation);
                            }
                          
                            /**
                             * @dev Upgrade the backing implementation of the proxy and call a function
                             * on the new implementation.
                             * This is useful to initialize the proxied contract.
                             * @param newImplementation Address of the new implementation.
                             * @param data Data to send as msg.data in the low level call.
                             * It should include the signature and the parameters of the function to be
                             * called, as described in
                             * https://solidity.readthedocs.io/en/develop/abi-spec.html#function-selector-and-argument-encoding.
                             */
                            function upgradeToAndCall(address newImplementation, bytes data) payable external ifAdmin {
                              _upgradeTo(newImplementation);
                              require(address(this).call.value(msg.value)(data));
                            }
                          
                            /**
                             * @return The admin slot.
                             */
                            function _admin() internal view returns (address adm) {
                              bytes32 slot = ADMIN_SLOT;
                              assembly {
                                adm := sload(slot)
                              }
                            }
                          
                            /**
                             * @dev Sets the address of the proxy admin.
                             * @param newAdmin Address of the new proxy admin.
                             */
                            function _setAdmin(address newAdmin) internal {
                              bytes32 slot = ADMIN_SLOT;
                          
                              assembly {
                                sstore(slot, newAdmin)
                              }
                            }
                          
                            /**
                             * @dev Only fall back when the sender is not the admin.
                             */
                            function _willFallback() internal {
                              require(msg.sender != _admin(), "Cannot call fallback function from the proxy admin");
                              super._willFallback();
                            }
                          }
                          
                          // File: contracts/FiatTokenProxy.sol
                          
                          /**
                          * Copyright CENTRE SECZ 2018
                          *
                          * Permission is hereby granted, free of charge, to any person obtaining a copy 
                          * of this software and associated documentation files (the "Software"), to deal 
                          * in the Software without restriction, including without limitation the rights 
                          * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell 
                          * copies of the Software, and to permit persons to whom the Software is furnished to 
                          * do so, subject to the following conditions:
                          *
                          * The above copyright notice and this permission notice shall be included in all 
                          * copies or substantial portions of the Software.
                          *
                          * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 
                          * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 
                          * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE 
                          * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
                          * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN 
                          * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
                          */
                          
                          pragma solidity ^0.4.24;
                          
                          
                          /**
                           * @title FiatTokenProxy
                           * @dev This contract proxies FiatToken calls and enables FiatToken upgrades
                          */ 
                          contract FiatTokenProxy is AdminUpgradeabilityProxy {
                              constructor(address _implementation) public AdminUpgradeabilityProxy(_implementation) {
                              }
                          }

                          File 2 of 5: TetherToken
                          pragma solidity ^0.4.17;
                          
                          /**
                           * @title SafeMath
                           * @dev Math operations with safety checks that throw on error
                           */
                          library SafeMath {
                              function mul(uint256 a, uint256 b) internal pure returns (uint256) {
                                  if (a == 0) {
                                      return 0;
                                  }
                                  uint256 c = a * b;
                                  assert(c / a == b);
                                  return c;
                              }
                          
                              function div(uint256 a, uint256 b) internal pure returns (uint256) {
                                  // assert(b > 0); // Solidity automatically throws when dividing by 0
                                  uint256 c = a / b;
                                  // assert(a == b * c + a % b); // There is no case in which this doesn't hold
                                  return c;
                              }
                          
                              function sub(uint256 a, uint256 b) internal pure returns (uint256) {
                                  assert(b <= a);
                                  return a - b;
                              }
                          
                              function add(uint256 a, uint256 b) internal pure returns (uint256) {
                                  uint256 c = a + b;
                                  assert(c >= a);
                                  return c;
                              }
                          }
                          
                          /**
                           * @title Ownable
                           * @dev The Ownable contract has an owner address, and provides basic authorization control
                           * functions, this simplifies the implementation of "user permissions".
                           */
                          contract Ownable {
                              address public owner;
                          
                              /**
                                * @dev The Ownable constructor sets the original `owner` of the contract to the sender
                                * account.
                                */
                              function Ownable() public {
                                  owner = msg.sender;
                              }
                          
                              /**
                                * @dev Throws if called by any account other than the owner.
                                */
                              modifier onlyOwner() {
                                  require(msg.sender == owner);
                                  _;
                              }
                          
                              /**
                              * @dev Allows the current owner to transfer control of the contract to a newOwner.
                              * @param newOwner The address to transfer ownership to.
                              */
                              function transferOwnership(address newOwner) public onlyOwner {
                                  if (newOwner != address(0)) {
                                      owner = newOwner;
                                  }
                              }
                          
                          }
                          
                          /**
                           * @title ERC20Basic
                           * @dev Simpler version of ERC20 interface
                           * @dev see https://github.com/ethereum/EIPs/issues/20
                           */
                          contract ERC20Basic {
                              uint public _totalSupply;
                              function totalSupply() public constant returns (uint);
                              function balanceOf(address who) public constant returns (uint);
                              function transfer(address to, uint value) public;
                              event Transfer(address indexed from, address indexed to, uint value);
                          }
                          
                          /**
                           * @title ERC20 interface
                           * @dev see https://github.com/ethereum/EIPs/issues/20
                           */
                          contract ERC20 is ERC20Basic {
                              function allowance(address owner, address spender) public constant returns (uint);
                              function transferFrom(address from, address to, uint value) public;
                              function approve(address spender, uint value) public;
                              event Approval(address indexed owner, address indexed spender, uint value);
                          }
                          
                          /**
                           * @title Basic token
                           * @dev Basic version of StandardToken, with no allowances.
                           */
                          contract BasicToken is Ownable, ERC20Basic {
                              using SafeMath for uint;
                          
                              mapping(address => uint) public balances;
                          
                              // additional variables for use if transaction fees ever became necessary
                              uint public basisPointsRate = 0;
                              uint public maximumFee = 0;
                          
                              /**
                              * @dev Fix for the ERC20 short address attack.
                              */
                              modifier onlyPayloadSize(uint size) {
                                  require(!(msg.data.length < size + 4));
                                  _;
                              }
                          
                              /**
                              * @dev transfer token for a specified address
                              * @param _to The address to transfer to.
                              * @param _value The amount to be transferred.
                              */
                              function transfer(address _to, uint _value) public onlyPayloadSize(2 * 32) {
                                  uint fee = (_value.mul(basisPointsRate)).div(10000);
                                  if (fee > maximumFee) {
                                      fee = maximumFee;
                                  }
                                  uint sendAmount = _value.sub(fee);
                                  balances[msg.sender] = balances[msg.sender].sub(_value);
                                  balances[_to] = balances[_to].add(sendAmount);
                                  if (fee > 0) {
                                      balances[owner] = balances[owner].add(fee);
                                      Transfer(msg.sender, owner, fee);
                                  }
                                  Transfer(msg.sender, _to, sendAmount);
                              }
                          
                              /**
                              * @dev Gets the balance of the specified address.
                              * @param _owner The address to query the the balance of.
                              * @return An uint representing the amount owned by the passed address.
                              */
                              function balanceOf(address _owner) public constant returns (uint balance) {
                                  return balances[_owner];
                              }
                          
                          }
                          
                          /**
                           * @title Standard ERC20 token
                           *
                           * @dev Implementation of the basic standard token.
                           * @dev https://github.com/ethereum/EIPs/issues/20
                           * @dev Based oncode by FirstBlood: https://github.com/Firstbloodio/token/blob/master/smart_contract/FirstBloodToken.sol
                           */
                          contract StandardToken is BasicToken, ERC20 {
                          
                              mapping (address => mapping (address => uint)) public allowed;
                          
                              uint public constant MAX_UINT = 2**256 - 1;
                          
                              /**
                              * @dev Transfer tokens from one address to another
                              * @param _from address The address which you want to send tokens from
                              * @param _to address The address which you want to transfer to
                              * @param _value uint the amount of tokens to be transferred
                              */
                              function transferFrom(address _from, address _to, uint _value) public onlyPayloadSize(3 * 32) {
                                  var _allowance = allowed[_from][msg.sender];
                          
                                  // Check is not needed because sub(_allowance, _value) will already throw if this condition is not met
                                  // if (_value > _allowance) throw;
                          
                                  uint fee = (_value.mul(basisPointsRate)).div(10000);
                                  if (fee > maximumFee) {
                                      fee = maximumFee;
                                  }
                                  if (_allowance < MAX_UINT) {
                                      allowed[_from][msg.sender] = _allowance.sub(_value);
                                  }
                                  uint sendAmount = _value.sub(fee);
                                  balances[_from] = balances[_from].sub(_value);
                                  balances[_to] = balances[_to].add(sendAmount);
                                  if (fee > 0) {
                                      balances[owner] = balances[owner].add(fee);
                                      Transfer(_from, owner, fee);
                                  }
                                  Transfer(_from, _to, sendAmount);
                              }
                          
                              /**
                              * @dev Approve the passed address to spend the specified amount of tokens on behalf of msg.sender.
                              * @param _spender The address which will spend the funds.
                              * @param _value The amount of tokens to be spent.
                              */
                              function approve(address _spender, uint _value) public onlyPayloadSize(2 * 32) {
                          
                                  // To change the approve amount you first have to reduce the addresses`
                                  //  allowance to zero by calling `approve(_spender, 0)` if it is not
                                  //  already 0 to mitigate the race condition described here:
                                  //  https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729
                                  require(!((_value != 0) && (allowed[msg.sender][_spender] != 0)));
                          
                                  allowed[msg.sender][_spender] = _value;
                                  Approval(msg.sender, _spender, _value);
                              }
                          
                              /**
                              * @dev Function to check the amount of tokens than an owner allowed to a spender.
                              * @param _owner address The address which owns the funds.
                              * @param _spender address The address which will spend the funds.
                              * @return A uint specifying the amount of tokens still available for the spender.
                              */
                              function allowance(address _owner, address _spender) public constant returns (uint remaining) {
                                  return allowed[_owner][_spender];
                              }
                          
                          }
                          
                          
                          /**
                           * @title Pausable
                           * @dev Base contract which allows children to implement an emergency stop mechanism.
                           */
                          contract Pausable is Ownable {
                            event Pause();
                            event Unpause();
                          
                            bool public paused = false;
                          
                          
                            /**
                             * @dev Modifier to make a function callable only when the contract is not paused.
                             */
                            modifier whenNotPaused() {
                              require(!paused);
                              _;
                            }
                          
                            /**
                             * @dev Modifier to make a function callable only when the contract is paused.
                             */
                            modifier whenPaused() {
                              require(paused);
                              _;
                            }
                          
                            /**
                             * @dev called by the owner to pause, triggers stopped state
                             */
                            function pause() onlyOwner whenNotPaused public {
                              paused = true;
                              Pause();
                            }
                          
                            /**
                             * @dev called by the owner to unpause, returns to normal state
                             */
                            function unpause() onlyOwner whenPaused public {
                              paused = false;
                              Unpause();
                            }
                          }
                          
                          contract BlackList is Ownable, BasicToken {
                          
                              /////// Getters to allow the same blacklist to be used also by other contracts (including upgraded Tether) ///////
                              function getBlackListStatus(address _maker) external constant returns (bool) {
                                  return isBlackListed[_maker];
                              }
                          
                              function getOwner() external constant returns (address) {
                                  return owner;
                              }
                          
                              mapping (address => bool) public isBlackListed;
                              
                              function addBlackList (address _evilUser) public onlyOwner {
                                  isBlackListed[_evilUser] = true;
                                  AddedBlackList(_evilUser);
                              }
                          
                              function removeBlackList (address _clearedUser) public onlyOwner {
                                  isBlackListed[_clearedUser] = false;
                                  RemovedBlackList(_clearedUser);
                              }
                          
                              function destroyBlackFunds (address _blackListedUser) public onlyOwner {
                                  require(isBlackListed[_blackListedUser]);
                                  uint dirtyFunds = balanceOf(_blackListedUser);
                                  balances[_blackListedUser] = 0;
                                  _totalSupply -= dirtyFunds;
                                  DestroyedBlackFunds(_blackListedUser, dirtyFunds);
                              }
                          
                              event DestroyedBlackFunds(address _blackListedUser, uint _balance);
                          
                              event AddedBlackList(address _user);
                          
                              event RemovedBlackList(address _user);
                          
                          }
                          
                          contract UpgradedStandardToken is StandardToken{
                              // those methods are called by the legacy contract
                              // and they must ensure msg.sender to be the contract address
                              function transferByLegacy(address from, address to, uint value) public;
                              function transferFromByLegacy(address sender, address from, address spender, uint value) public;
                              function approveByLegacy(address from, address spender, uint value) public;
                          }
                          
                          contract TetherToken is Pausable, StandardToken, BlackList {
                          
                              string public name;
                              string public symbol;
                              uint public decimals;
                              address public upgradedAddress;
                              bool public deprecated;
                          
                              //  The contract can be initialized with a number of tokens
                              //  All the tokens are deposited to the owner address
                              //
                              // @param _balance Initial supply of the contract
                              // @param _name Token Name
                              // @param _symbol Token symbol
                              // @param _decimals Token decimals
                              function TetherToken(uint _initialSupply, string _name, string _symbol, uint _decimals) public {
                                  _totalSupply = _initialSupply;
                                  name = _name;
                                  symbol = _symbol;
                                  decimals = _decimals;
                                  balances[owner] = _initialSupply;
                                  deprecated = false;
                              }
                          
                              // Forward ERC20 methods to upgraded contract if this one is deprecated
                              function transfer(address _to, uint _value) public whenNotPaused {
                                  require(!isBlackListed[msg.sender]);
                                  if (deprecated) {
                                      return UpgradedStandardToken(upgradedAddress).transferByLegacy(msg.sender, _to, _value);
                                  } else {
                                      return super.transfer(_to, _value);
                                  }
                              }
                          
                              // Forward ERC20 methods to upgraded contract if this one is deprecated
                              function transferFrom(address _from, address _to, uint _value) public whenNotPaused {
                                  require(!isBlackListed[_from]);
                                  if (deprecated) {
                                      return UpgradedStandardToken(upgradedAddress).transferFromByLegacy(msg.sender, _from, _to, _value);
                                  } else {
                                      return super.transferFrom(_from, _to, _value);
                                  }
                              }
                          
                              // Forward ERC20 methods to upgraded contract if this one is deprecated
                              function balanceOf(address who) public constant returns (uint) {
                                  if (deprecated) {
                                      return UpgradedStandardToken(upgradedAddress).balanceOf(who);
                                  } else {
                                      return super.balanceOf(who);
                                  }
                              }
                          
                              // Forward ERC20 methods to upgraded contract if this one is deprecated
                              function approve(address _spender, uint _value) public onlyPayloadSize(2 * 32) {
                                  if (deprecated) {
                                      return UpgradedStandardToken(upgradedAddress).approveByLegacy(msg.sender, _spender, _value);
                                  } else {
                                      return super.approve(_spender, _value);
                                  }
                              }
                          
                              // Forward ERC20 methods to upgraded contract if this one is deprecated
                              function allowance(address _owner, address _spender) public constant returns (uint remaining) {
                                  if (deprecated) {
                                      return StandardToken(upgradedAddress).allowance(_owner, _spender);
                                  } else {
                                      return super.allowance(_owner, _spender);
                                  }
                              }
                          
                              // deprecate current contract in favour of a new one
                              function deprecate(address _upgradedAddress) public onlyOwner {
                                  deprecated = true;
                                  upgradedAddress = _upgradedAddress;
                                  Deprecate(_upgradedAddress);
                              }
                          
                              // deprecate current contract if favour of a new one
                              function totalSupply() public constant returns (uint) {
                                  if (deprecated) {
                                      return StandardToken(upgradedAddress).totalSupply();
                                  } else {
                                      return _totalSupply;
                                  }
                              }
                          
                              // Issue a new amount of tokens
                              // these tokens are deposited into the owner address
                              //
                              // @param _amount Number of tokens to be issued
                              function issue(uint amount) public onlyOwner {
                                  require(_totalSupply + amount > _totalSupply);
                                  require(balances[owner] + amount > balances[owner]);
                          
                                  balances[owner] += amount;
                                  _totalSupply += amount;
                                  Issue(amount);
                              }
                          
                              // Redeem tokens.
                              // These tokens are withdrawn from the owner address
                              // if the balance must be enough to cover the redeem
                              // or the call will fail.
                              // @param _amount Number of tokens to be issued
                              function redeem(uint amount) public onlyOwner {
                                  require(_totalSupply >= amount);
                                  require(balances[owner] >= amount);
                          
                                  _totalSupply -= amount;
                                  balances[owner] -= amount;
                                  Redeem(amount);
                              }
                          
                              function setParams(uint newBasisPoints, uint newMaxFee) public onlyOwner {
                                  // Ensure transparency by hardcoding limit beyond which fees can never be added
                                  require(newBasisPoints < 20);
                                  require(newMaxFee < 50);
                          
                                  basisPointsRate = newBasisPoints;
                                  maximumFee = newMaxFee.mul(10**decimals);
                          
                                  Params(basisPointsRate, maximumFee);
                              }
                          
                              // Called when new token are issued
                              event Issue(uint amount);
                          
                              // Called when tokens are redeemed
                              event Redeem(uint amount);
                          
                              // Called when contract is deprecated
                              event Deprecate(address newAddress);
                          
                              // Called if contract ever adds fees
                              event Params(uint feeBasisPoints, uint maxFee);
                          }

                          File 3 of 5: FetchToken
                          // SPDX-License-Identifier: Apache-2.0
                          pragma solidity 0.6.2;
                          
                          /**
                           * @dev Library for managing
                           * https://en.wikipedia.org/wiki/Set_(abstract_data_type)[sets] of primitive
                           * types.
                           *
                           * Sets have the following properties:
                           *
                           * - Elements are added, removed, and checked for existence in constant time
                           * (O(1)).
                           * - Elements are enumerated in O(n). No guarantees are made on the ordering.
                           *
                           * ```
                           * contract Example {
                           *     // Add the library methods
                           *     using EnumerableSet for EnumerableSet.AddressSet;
                           *
                           *     // Declare a set state variable
                           *     EnumerableSet.AddressSet private mySet;
                           * }
                           * ```
                           *
                           * As of v3.0.0, only sets of type `address` (`AddressSet`) and `uint256`
                           * (`UintSet`) are supported.
                           */
                          library EnumerableSet {
                              // To implement this library for multiple types with as little code
                              // repetition as possible, we write it in terms of a generic Set type with
                              // bytes32 values.
                              // The Set implementation uses private functions, and user-facing
                              // implementations (such as AddressSet) are just wrappers around the
                              // underlying Set.
                              // This means that we can only create new EnumerableSets for types that fit
                              // in bytes32.
                          
                              struct Set {
                                  // Storage of set values
                                  bytes32[] _values;
                          
                                  // Position of the value in the `values` array, plus 1 because index 0
                                  // means a value is not in the set.
                                  mapping (bytes32 => uint256) _indexes;
                              }
                          
                              /**
                               * @dev Add a value to a set. O(1).
                               *
                               * Returns true if the value was added to the set, that is if it was not
                               * already present.
                               */
                              function _add(Set storage set, bytes32 value) private returns (bool) {
                                  if (!_contains(set, value)) {
                                      set._values.push(value);
                                      // The value is stored at length-1, but we add 1 to all indexes
                                      // and use 0 as a sentinel value
                                      set._indexes[value] = set._values.length;
                                      return true;
                                  } else {
                                      return false;
                                  }
                              }
                          
                              /**
                               * @dev Removes a value from a set. O(1).
                               *
                               * Returns true if the value was removed from the set, that is if it was
                               * present.
                               */
                              function _remove(Set storage set, bytes32 value) private returns (bool) {
                                  // We read and store the value's index to prevent multiple reads from the same storage slot
                                  uint256 valueIndex = set._indexes[value];
                          
                                  if (valueIndex != 0) { // Equivalent to contains(set, value)
                                      // To delete an element from the _values array in O(1), we swap the element to delete with the last one in
                                      // the array, and then remove the last element (sometimes called as 'swap and pop').
                                      // This modifies the order of the array, as noted in {at}.
                          
                                      uint256 toDeleteIndex = valueIndex - 1;
                                      uint256 lastIndex = set._values.length - 1;
                          
                                      // When the value to delete is the last one, the swap operation is unnecessary. However, since this occurs
                                      // so rarely, we still do the swap anyway to avoid the gas cost of adding an 'if' statement.
                          
                                      bytes32 lastvalue = set._values[lastIndex];
                          
                                      // Move the last value to the index where the value to delete is
                                      set._values[toDeleteIndex] = lastvalue;
                                      // Update the index for the moved value
                                      set._indexes[lastvalue] = toDeleteIndex + 1; // All indexes are 1-based
                          
                                      // Delete the slot where the moved value was stored
                                      set._values.pop();
                          
                                      // Delete the index for the deleted slot
                                      delete set._indexes[value];
                          
                                      return true;
                                  } else {
                                      return false;
                                  }
                              }
                          
                              /**
                               * @dev Returns true if the value is in the set. O(1).
                               */
                              function _contains(Set storage set, bytes32 value) private view returns (bool) {
                                  return set._indexes[value] != 0;
                              }
                          
                              /**
                               * @dev Returns the number of values on the set. O(1).
                               */
                              function _length(Set storage set) private view returns (uint256) {
                                  return set._values.length;
                              }
                          
                             /**
                              * @dev Returns the value stored at position `index` in the set. O(1).
                              *
                              * Note that there are no guarantees on the ordering of values inside the
                              * array, and it may change when more values are added or removed.
                              *
                              * Requirements:
                              *
                              * - `index` must be strictly less than {length}.
                              */
                              function _at(Set storage set, uint256 index) private view returns (bytes32) {
                                  require(set._values.length > index, "EnumerableSet: index out of bounds");
                                  return set._values[index];
                              }
                          
                              // AddressSet
                          
                              struct AddressSet {
                                  Set _inner;
                              }
                          
                              /**
                               * @dev Add a value to a set. O(1).
                               *
                               * Returns true if the value was added to the set, that is if it was not
                               * already present.
                               */
                              function add(AddressSet storage set, address value) internal returns (bool) {
                                  return _add(set._inner, bytes32(uint256(value)));
                              }
                          
                              /**
                               * @dev Removes a value from a set. O(1).
                               *
                               * Returns true if the value was removed from the set, that is if it was
                               * present.
                               */
                              function remove(AddressSet storage set, address value) internal returns (bool) {
                                  return _remove(set._inner, bytes32(uint256(value)));
                              }
                          
                              /**
                               * @dev Returns true if the value is in the set. O(1).
                               */
                              function contains(AddressSet storage set, address value) internal view returns (bool) {
                                  return _contains(set._inner, bytes32(uint256(value)));
                              }
                          
                              /**
                               * @dev Returns the number of values in the set. O(1).
                               */
                              function length(AddressSet storage set) internal view returns (uint256) {
                                  return _length(set._inner);
                              }
                          
                             /**
                              * @dev Returns the value stored at position `index` in the set. O(1).
                              *
                              * Note that there are no guarantees on the ordering of values inside the
                              * array, and it may change when more values are added or removed.
                              *
                              * Requirements:
                              *
                              * - `index` must be strictly less than {length}.
                              */
                              function at(AddressSet storage set, uint256 index) internal view returns (address) {
                                  return address(uint256(_at(set._inner, index)));
                              }
                          
                          
                              // UintSet
                          
                              struct UintSet {
                                  Set _inner;
                              }
                          
                              /**
                               * @dev Add a value to a set. O(1).
                               *
                               * Returns true if the value was added to the set, that is if it was not
                               * already present.
                               */
                              function add(UintSet storage set, uint256 value) internal returns (bool) {
                                  return _add(set._inner, bytes32(value));
                              }
                          
                              /**
                               * @dev Removes a value from a set. O(1).
                               *
                               * Returns true if the value was removed from the set, that is if it was
                               * present.
                               */
                              function remove(UintSet storage set, uint256 value) internal returns (bool) {
                                  return _remove(set._inner, bytes32(value));
                              }
                          
                              /**
                               * @dev Returns true if the value is in the set. O(1).
                               */
                              function contains(UintSet storage set, uint256 value) internal view returns (bool) {
                                  return _contains(set._inner, bytes32(value));
                              }
                          
                              /**
                               * @dev Returns the number of values on the set. O(1).
                               */
                              function length(UintSet storage set) internal view returns (uint256) {
                                  return _length(set._inner);
                              }
                          
                             /**
                              * @dev Returns the value stored at position `index` in the set. O(1).
                              *
                              * Note that there are no guarantees on the ordering of values inside the
                              * array, and it may change when more values are added or removed.
                              *
                              * Requirements:
                              *
                              * - `index` must be strictly less than {length}.
                              */
                              function at(UintSet storage set, uint256 index) internal view returns (uint256) {
                                  return uint256(_at(set._inner, index));
                              }
                          }
                          
                          /**
                           * @dev Collection of functions related to the address type
                           */
                          library Address {
                              /**
                               * @dev Returns true if `account` is a contract.
                               *
                               * [IMPORTANT]
                               * ====
                               * It is unsafe to assume that an address for which this function returns
                               * false is an externally-owned account (EOA) and not a contract.
                               *
                               * Among others, `isContract` will return false for the following
                               * types of addresses:
                               *
                               *  - an externally-owned account
                               *  - a contract in construction
                               *  - an address where a contract will be created
                               *  - an address where a contract lived, but was destroyed
                               * ====
                               */
                              function isContract(address account) internal view returns (bool) {
                                  // According to EIP-1052, 0x0 is the value returned for not-yet created accounts
                                  // and 0xc5d2460186f7233c927e7db2dcc703c0e500b653ca82273b7bfad8045d85a470 is returned
                                  // for accounts without code, i.e. `keccak256('')`
                                  bytes32 codehash;
                                  bytes32 accountHash = 0xc5d2460186f7233c927e7db2dcc703c0e500b653ca82273b7bfad8045d85a470;
                                  // solhint-disable-next-line no-inline-assembly
                                  assembly { codehash := extcodehash(account) }
                                  return (codehash != accountHash && codehash != 0x0);
                              }
                          
                              /**
                               * @dev Replacement for Solidity's `transfer`: sends `amount` wei to
                               * `recipient`, forwarding all available gas and reverting on errors.
                               *
                               * https://eips.ethereum.org/EIPS/eip-1884[EIP1884] increases the gas cost
                               * of certain opcodes, possibly making contracts go over the 2300 gas limit
                               * imposed by `transfer`, making them unable to receive funds via
                               * `transfer`. {sendValue} removes this limitation.
                               *
                               * https://diligence.consensys.net/posts/2019/09/stop-using-soliditys-transfer-now/[Learn more].
                               *
                               * IMPORTANT: because control is transferred to `recipient`, care must be
                               * taken to not create reentrancy vulnerabilities. Consider using
                               * {ReentrancyGuard} or the
                               * https://solidity.readthedocs.io/en/v0.5.11/security-considerations.html#use-the-checks-effects-interactions-pattern[checks-effects-interactions pattern].
                               */
                              function sendValue(address payable recipient, uint256 amount) internal {
                                  require(address(this).balance >= amount, "Address: insufficient balance");
                          
                                  // solhint-disable-next-line avoid-low-level-calls, avoid-call-value
                                  (bool success, ) = recipient.call{ value: amount }("");
                                  require(success, "Address: unable to send value, recipient may have reverted");
                              }
                          }
                          
                          /*
                           * @dev Provides information about the current execution context, including the
                           * sender of the transaction and its data. While these are generally available
                           * via msg.sender and msg.data, they should not be accessed in such a direct
                           * manner, since when dealing with GSN meta-transactions the account sending and
                           * paying for execution may not be the actual sender (as far as an application
                           * is concerned).
                           *
                           * This contract is only required for intermediate, library-like contracts.
                           */
                          contract Context {
                              // Empty internal constructor, to prevent people from mistakenly deploying
                              // an instance of this contract, which should be used via inheritance.
                              constructor () internal { }
                          
                              function _msgSender() internal view virtual returns (address payable) {
                                  return msg.sender;
                              }
                          
                              function _msgData() internal view virtual returns (bytes memory) {
                                  this; // silence state mutability warning without generating bytecode - see https://github.com/ethereum/solidity/issues/2691
                                  return msg.data;
                              }
                          }
                          
                          /**
                           * @dev Contract module that allows children to implement role-based access
                           * control mechanisms.
                           *
                           * Roles are referred to by their `bytes32` identifier. These should be exposed
                           * in the external API and be unique. The best way to achieve this is by
                           * using `public constant` hash digests:
                           *
                           * ```
                           * bytes32 public constant MY_ROLE = keccak256("MY_ROLE");
                           * ```
                           *
                           * Roles can be used to represent a set of permissions. To restrict access to a
                           * function call, use {hasRole}:
                           *
                           * ```
                           * function foo() public {
                           *     require(hasRole(MY_ROLE, _msgSender()));
                           *     ...
                           * }
                           * ```
                           *
                           * Roles can be granted and revoked dynamically via the {grantRole} and
                           * {revokeRole} functions. Each role has an associated admin role, and only
                           * accounts that have a role's admin role can call {grantRole} and {revokeRole}.
                           *
                           * By default, the admin role for all roles is `DEFAULT_ADMIN_ROLE`, which means
                           * that only accounts with this role will be able to grant or revoke other
                           * roles. More complex role relationships can be created by using
                           * {_setRoleAdmin}.
                           */
                          abstract contract AccessControl is Context {
                              using EnumerableSet for EnumerableSet.AddressSet;
                              using Address for address;
                          
                              struct RoleData {
                                  EnumerableSet.AddressSet members;
                                  bytes32 adminRole;
                              }
                          
                              mapping (bytes32 => RoleData) private _roles;
                          
                              bytes32 public constant DEFAULT_ADMIN_ROLE = 0x00;
                          
                              /**
                               * @dev Emitted when `account` is granted `role`.
                               *
                               * `sender` is the account that originated the contract call, an admin role
                               * bearer except when using {_setupRole}.
                               */
                              event RoleGranted(bytes32 indexed role, address indexed account, address indexed sender);
                          
                              /**
                               * @dev Emitted when `account` is revoked `role`.
                               *
                               * `sender` is the account that originated the contract call:
                               *   - if using `revokeRole`, it is the admin role bearer
                               *   - if using `renounceRole`, it is the role bearer (i.e. `account`)
                               */
                              event RoleRevoked(bytes32 indexed role, address indexed account, address indexed sender);
                          
                              /**
                               * @dev Returns `true` if `account` has been granted `role`.
                               */
                              function hasRole(bytes32 role, address account) public view returns (bool) {
                                  return _roles[role].members.contains(account);
                              }
                          
                              /**
                               * @dev Returns the number of accounts that have `role`. Can be used
                               * together with {getRoleMember} to enumerate all bearers of a role.
                               */
                              function getRoleMemberCount(bytes32 role) public view returns (uint256) {
                                  return _roles[role].members.length();
                              }
                          
                              /**
                               * @dev Returns one of the accounts that have `role`. `index` must be a
                               * value between 0 and {getRoleMemberCount}, non-inclusive.
                               *
                               * Role bearers are not sorted in any particular way, and their ordering may
                               * change at any point.
                               *
                               * WARNING: When using {getRoleMember} and {getRoleMemberCount}, make sure
                               * you perform all queries on the same block. See the following
                               * https://forum.openzeppelin.com/t/iterating-over-elements-on-enumerableset-in-openzeppelin-contracts/2296[forum post]
                               * for more information.
                               */
                              function getRoleMember(bytes32 role, uint256 index) public view returns (address) {
                                  return _roles[role].members.at(index);
                              }
                          
                              /**
                               * @dev Returns the admin role that controls `role`. See {grantRole} and
                               * {revokeRole}.
                               *
                               * To change a role's admin, use {_setRoleAdmin}.
                               */
                              function getRoleAdmin(bytes32 role) public view returns (bytes32) {
                                  return _roles[role].adminRole;
                              }
                          
                              /**
                               * @dev Grants `role` to `account`.
                               *
                               * If `account` had not been already granted `role`, emits a {RoleGranted}
                               * event.
                               *
                               * Requirements:
                               *
                               * - the caller must have ``role``'s admin role.
                               */
                              function grantRole(bytes32 role, address account) public virtual {
                                  require(hasRole(_roles[role].adminRole, _msgSender()), "AccessControl: sender must be an admin to grant");
                          
                                  _grantRole(role, account);
                              }
                          
                              /**
                               * @dev Revokes `role` from `account`.
                               *
                               * If `account` had been granted `role`, emits a {RoleRevoked} event.
                               *
                               * Requirements:
                               *
                               * - the caller must have ``role``'s admin role.
                               */
                              function revokeRole(bytes32 role, address account) public virtual {
                                  require(hasRole(_roles[role].adminRole, _msgSender()), "AccessControl: sender must be an admin to revoke");
                          
                                  _revokeRole(role, account);
                              }
                          
                              /**
                               * @dev Revokes `role` from the calling account.
                               *
                               * Roles are often managed via {grantRole} and {revokeRole}: this function's
                               * purpose is to provide a mechanism for accounts to lose their privileges
                               * if they are compromised (such as when a trusted device is misplaced).
                               *
                               * If the calling account had been granted `role`, emits a {RoleRevoked}
                               * event.
                               *
                               * Requirements:
                               *
                               * - the caller must be `account`.
                               */
                              function renounceRole(bytes32 role, address account) public virtual {
                                  require(account == _msgSender(), "AccessControl: can only renounce roles for self");
                          
                                  _revokeRole(role, account);
                              }
                          
                              /**
                               * @dev Grants `role` to `account`.
                               *
                               * If `account` had not been already granted `role`, emits a {RoleGranted}
                               * event. Note that unlike {grantRole}, this function doesn't perform any
                               * checks on the calling account.
                               *
                               * [WARNING]
                               * ====
                               * This function should only be called from the constructor when setting
                               * up the initial roles for the system.
                               *
                               * Using this function in any other way is effectively circumventing the admin
                               * system imposed by {AccessControl}.
                               * ====
                               */
                              function _setupRole(bytes32 role, address account) internal virtual {
                                  _grantRole(role, account);
                              }
                          
                              /**
                               * @dev Sets `adminRole` as ``role``'s admin role.
                               */
                              function _setRoleAdmin(bytes32 role, bytes32 adminRole) internal virtual {
                                  _roles[role].adminRole = adminRole;
                              }
                          
                              function _grantRole(bytes32 role, address account) private {
                                  if (_roles[role].members.add(account)) {
                                      emit RoleGranted(role, account, _msgSender());
                                  }
                              }
                          
                              function _revokeRole(bytes32 role, address account) private {
                                  if (_roles[role].members.remove(account)) {
                                      emit RoleRevoked(role, account, _msgSender());
                                  }
                              }
                          }
                          
                          
                          
                          /**
                           * @dev Interface of the ERC20 standard as defined in the EIP.
                           */
                          interface IERC20 {
                              /**
                               * @dev Returns the amount of tokens in existence.
                               */
                              function totalSupply() external view returns (uint256);
                          
                              /**
                               * @dev Returns the amount of tokens owned by `account`.
                               */
                              function balanceOf(address account) external view returns (uint256);
                          
                              /**
                               * @dev Moves `amount` tokens from the caller's account to `recipient`.
                               *
                               * Returns a boolean value indicating whether the operation succeeded.
                               *
                               * Emits a {Transfer} event.
                               */
                              function transfer(address recipient, uint256 amount) external returns (bool);
                          
                              /**
                               * @dev Returns the remaining number of tokens that `spender` will be
                               * allowed to spend on behalf of `owner` through {transferFrom}. This is
                               * zero by default.
                               *
                               * This value changes when {approve} or {transferFrom} are called.
                               */
                              function allowance(address owner, address spender) external view returns (uint256);
                          
                              /**
                               * @dev Sets `amount` as the allowance of `spender` over the caller's tokens.
                               *
                               * Returns a boolean value indicating whether the operation succeeded.
                               *
                               * IMPORTANT: Beware that changing an allowance with this method brings the risk
                               * that someone may use both the old and the new allowance by unfortunate
                               * transaction ordering. One possible solution to mitigate this race
                               * condition is to first reduce the spender's allowance to 0 and set the
                               * desired value afterwards:
                               * https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729
                               *
                               * Emits an {Approval} event.
                               */
                              function approve(address spender, uint256 amount) external returns (bool);
                          
                              /**
                               * @dev Moves `amount` tokens from `sender` to `recipient` using the
                               * allowance mechanism. `amount` is then deducted from the caller's
                               * allowance.
                               *
                               * Returns a boolean value indicating whether the operation succeeded.
                               *
                               * Emits a {Transfer} event.
                               */
                              function transferFrom(address sender, address recipient, uint256 amount) external returns (bool);
                          
                              /**
                               * @dev Emitted when `value` tokens are moved from one account (`from`) to
                               * another (`to`).
                               *
                               * Note that `value` may be zero.
                               */
                              event Transfer(address indexed from, address indexed to, uint256 value);
                          
                              /**
                               * @dev Emitted when the allowance of a `spender` for an `owner` is set by
                               * a call to {approve}. `value` is the new allowance.
                               */
                              event Approval(address indexed owner, address indexed spender, uint256 value);
                          }
                          
                          /**
                           * @dev Wrappers over Solidity's arithmetic operations with added overflow
                           * checks.
                           *
                           * Arithmetic operations in Solidity wrap on overflow. This can easily result
                           * in bugs, because programmers usually assume that an overflow raises an
                           * error, which is the standard behavior in high level programming languages.
                           * `SafeMath` restores this intuition by reverting the transaction when an
                           * operation overflows.
                           *
                           * Using this library instead of the unchecked operations eliminates an entire
                           * class of bugs, so it's recommended to use it always.
                           */
                          library SafeMath {
                              /**
                               * @dev Returns the addition of two unsigned integers, reverting on
                               * overflow.
                               *
                               * Counterpart to Solidity's `+` operator.
                               *
                               * Requirements:
                               * - Addition cannot overflow.
                               */
                              function add(uint256 a, uint256 b) internal pure returns (uint256) {
                                  uint256 c = a + b;
                                  require(c >= a, "SafeMath: addition overflow");
                          
                                  return c;
                              }
                          
                              /**
                               * @dev Returns the subtraction of two unsigned integers, reverting on
                               * overflow (when the result is negative).
                               *
                               * Counterpart to Solidity's `-` operator.
                               *
                               * Requirements:
                               * - Subtraction cannot overflow.
                               */
                              function sub(uint256 a, uint256 b) internal pure returns (uint256) {
                                  return sub(a, b, "SafeMath: subtraction overflow");
                              }
                          
                              /**
                               * @dev Returns the subtraction of two unsigned integers, reverting with custom message on
                               * overflow (when the result is negative).
                               *
                               * Counterpart to Solidity's `-` operator.
                               *
                               * Requirements:
                               * - Subtraction cannot overflow.
                               */
                              function sub(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
                                  require(b <= a, errorMessage);
                                  uint256 c = a - b;
                          
                                  return c;
                              }
                          
                              /**
                               * @dev Returns the multiplication of two unsigned integers, reverting on
                               * overflow.
                               *
                               * Counterpart to Solidity's `*` operator.
                               *
                               * Requirements:
                               * - Multiplication cannot overflow.
                               */
                              function mul(uint256 a, uint256 b) internal pure returns (uint256) {
                                  // Gas optimization: this is cheaper than requiring 'a' not being zero, but the
                                  // benefit is lost if 'b' is also tested.
                                  // See: https://github.com/OpenZeppelin/openzeppelin-contracts/pull/522
                                  if (a == 0) {
                                      return 0;
                                  }
                          
                                  uint256 c = a * b;
                                  require(c / a == b, "SafeMath: multiplication overflow");
                          
                                  return c;
                              }
                          
                              /**
                               * @dev Returns the integer division of two unsigned integers. Reverts on
                               * division by zero. The result is rounded towards zero.
                               *
                               * Counterpart to Solidity's `/` operator. Note: this function uses a
                               * `revert` opcode (which leaves remaining gas untouched) while Solidity
                               * uses an invalid opcode to revert (consuming all remaining gas).
                               *
                               * Requirements:
                               * - The divisor cannot be zero.
                               */
                              function div(uint256 a, uint256 b) internal pure returns (uint256) {
                                  return div(a, b, "SafeMath: division by zero");
                              }
                          
                              /**
                               * @dev Returns the integer division of two unsigned integers. Reverts with custom message on
                               * division by zero. The result is rounded towards zero.
                               *
                               * Counterpart to Solidity's `/` operator. Note: this function uses a
                               * `revert` opcode (which leaves remaining gas untouched) while Solidity
                               * uses an invalid opcode to revert (consuming all remaining gas).
                               *
                               * Requirements:
                               * - The divisor cannot be zero.
                               */
                              function div(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
                                  // Solidity only automatically asserts when dividing by 0
                                  require(b > 0, errorMessage);
                                  uint256 c = a / b;
                                  // assert(a == b * c + a % b); // There is no case in which this doesn't hold
                          
                                  return c;
                              }
                          
                              /**
                               * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
                               * Reverts when dividing by zero.
                               *
                               * Counterpart to Solidity's `%` operator. This function uses a `revert`
                               * opcode (which leaves remaining gas untouched) while Solidity uses an
                               * invalid opcode to revert (consuming all remaining gas).
                               *
                               * Requirements:
                               * - The divisor cannot be zero.
                               */
                              function mod(uint256 a, uint256 b) internal pure returns (uint256) {
                                  return mod(a, b, "SafeMath: modulo by zero");
                              }
                          
                              /**
                               * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
                               * Reverts with custom message when dividing by zero.
                               *
                               * Counterpart to Solidity's `%` operator. This function uses a `revert`
                               * opcode (which leaves remaining gas untouched) while Solidity uses an
                               * invalid opcode to revert (consuming all remaining gas).
                               *
                               * Requirements:
                               * - The divisor cannot be zero.
                               */
                              function mod(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
                                  require(b != 0, errorMessage);
                                  return a % b;
                              }
                          }
                          
                          /**
                           * @dev Implementation of the {IERC20} interface.
                           *
                           * This implementation is agnostic to the way tokens are created. This means
                           * that a supply mechanism has to be added in a derived contract using {_mint}.
                           * For a generic mechanism see {ERC20MinterPauser}.
                           *
                           * TIP: For a detailed writeup see our guide
                           * https://forum.zeppelin.solutions/t/how-to-implement-erc20-supply-mechanisms/226[How
                           * to implement supply mechanisms].
                           *
                           * We have followed general OpenZeppelin guidelines: functions revert instead
                           * of returning `false` on failure. This behavior is nonetheless conventional
                           * and does not conflict with the expectations of ERC20 applications.
                           *
                           * Additionally, an {Approval} event is emitted on calls to {transferFrom}.
                           * This allows applications to reconstruct the allowance for all accounts just
                           * by listening to said events. Other implementations of the EIP may not emit
                           * these events, as it isn't required by the specification.
                           *
                           * Finally, the non-standard {decreaseAllowance} and {increaseAllowance}
                           * functions have been added to mitigate the well-known issues around setting
                           * allowances. See {IERC20-approve}.
                           */
                          contract ERC20 is Context, IERC20 {
                              using SafeMath for uint256;
                              using Address for address;
                          
                              mapping (address => uint256) private _balances;
                          
                              mapping (address => mapping (address => uint256)) private _allowances;
                          
                              uint256 private _totalSupply;
                          
                              string private _name;
                              string private _symbol;
                              uint8 private _decimals;
                          
                              /**
                               * @dev Sets the values for {name} and {symbol}, initializes {decimals} with
                               * a default value of 18.
                               *
                               * To select a different value for {decimals}, use {_setupDecimals}.
                               *
                               * All three of these values are immutable: they can only be set once during
                               * construction.
                               */
                              constructor (string memory name, string memory symbol) public {
                                  _name = name;
                                  _symbol = symbol;
                                  _decimals = 18;
                              }
                          
                              /**
                               * @dev Returns the name of the token.
                               */
                              function name() public view returns (string memory) {
                                  return _name;
                              }
                          
                              /**
                               * @dev Returns the symbol of the token, usually a shorter version of the
                               * name.
                               */
                              function symbol() public view returns (string memory) {
                                  return _symbol;
                              }
                          
                              /**
                               * @dev Returns the number of decimals used to get its user representation.
                               * For example, if `decimals` equals `2`, a balance of `505` tokens should
                               * be displayed to a user as `5,05` (`505 / 10 ** 2`).
                               *
                               * Tokens usually opt for a value of 18, imitating the relationship between
                               * Ether and Wei. This is the value {ERC20} uses, unless {_setupDecimals} is
                               * called.
                               *
                               * NOTE: This information is only used for _display_ purposes: it in
                               * no way affects any of the arithmetic of the contract, including
                               * {IERC20-balanceOf} and {IERC20-transfer}.
                               */
                              function decimals() public view returns (uint8) {
                                  return _decimals;
                              }
                          
                              /**
                               * @dev See {IERC20-totalSupply}.
                               */
                              function totalSupply() public view override returns (uint256) {
                                  return _totalSupply;
                              }
                          
                              /**
                               * @dev See {IERC20-balanceOf}.
                               */
                              function balanceOf(address account) public view override returns (uint256) {
                                  return _balances[account];
                              }
                          
                              /**
                               * @dev See {IERC20-transfer}.
                               *
                               * Requirements:
                               *
                               * - `recipient` cannot be the zero address.
                               * - the caller must have a balance of at least `amount`.
                               */
                              function transfer(address recipient, uint256 amount) public virtual override returns (bool) {
                                  _transfer(_msgSender(), recipient, amount);
                                  return true;
                              }
                          
                              /**
                               * @dev See {IERC20-allowance}.
                               */
                              function allowance(address owner, address spender) public view virtual override returns (uint256) {
                                  return _allowances[owner][spender];
                              }
                          
                              /**
                               * @dev See {IERC20-approve}.
                               *
                               * Requirements:
                               *
                               * - `spender` cannot be the zero address.
                               */
                              function approve(address spender, uint256 amount) public virtual override returns (bool) {
                                  _approve(_msgSender(), spender, amount);
                                  return true;
                              }
                          
                              /**
                               * @dev See {IERC20-transferFrom}.
                               *
                               * Emits an {Approval} event indicating the updated allowance. This is not
                               * required by the EIP. See the note at the beginning of {ERC20};
                               *
                               * Requirements:
                               * - `sender` and `recipient` cannot be the zero address.
                               * - `sender` must have a balance of at least `amount`.
                               * - the caller must have allowance for ``sender``'s tokens of at least
                               * `amount`.
                               */
                              function transferFrom(address sender, address recipient, uint256 amount) public virtual override returns (bool) {
                                  _transfer(sender, recipient, amount);
                                  _approve(sender, _msgSender(), _allowances[sender][_msgSender()].sub(amount, "ERC20: transfer amount exceeds allowance"));
                                  return true;
                              }
                          
                              /**
                               * @dev Atomically increases the allowance granted to `spender` by the caller.
                               *
                               * This is an alternative to {approve} that can be used as a mitigation for
                               * problems described in {IERC20-approve}.
                               *
                               * Emits an {Approval} event indicating the updated allowance.
                               *
                               * Requirements:
                               *
                               * - `spender` cannot be the zero address.
                               */
                              function increaseAllowance(address spender, uint256 addedValue) public virtual returns (bool) {
                                  _approve(_msgSender(), spender, _allowances[_msgSender()][spender].add(addedValue));
                                  return true;
                              }
                          
                              /**
                               * @dev Atomically decreases the allowance granted to `spender` by the caller.
                               *
                               * This is an alternative to {approve} that can be used as a mitigation for
                               * problems described in {IERC20-approve}.
                               *
                               * Emits an {Approval} event indicating the updated allowance.
                               *
                               * Requirements:
                               *
                               * - `spender` cannot be the zero address.
                               * - `spender` must have allowance for the caller of at least
                               * `subtractedValue`.
                               */
                              function decreaseAllowance(address spender, uint256 subtractedValue) public virtual returns (bool) {
                                  _approve(_msgSender(), spender, _allowances[_msgSender()][spender].sub(subtractedValue, "ERC20: decreased allowance below zero"));
                                  return true;
                              }
                          
                              /**
                               * @dev Moves tokens `amount` from `sender` to `recipient`.
                               *
                               * This is internal function is equivalent to {transfer}, and can be used to
                               * e.g. implement automatic token fees, slashing mechanisms, etc.
                               *
                               * Emits a {Transfer} event.
                               *
                               * Requirements:
                               *
                               * - `sender` cannot be the zero address.
                               * - `recipient` cannot be the zero address.
                               * - `sender` must have a balance of at least `amount`.
                               */
                              function _transfer(address sender, address recipient, uint256 amount) internal virtual {
                                  require(sender != address(0), "ERC20: transfer from the zero address");
                                  require(recipient != address(0), "ERC20: transfer to the zero address");
                          
                                  _beforeTokenTransfer(sender, recipient, amount);
                          
                                  _balances[sender] = _balances[sender].sub(amount, "ERC20: transfer amount exceeds balance");
                                  _balances[recipient] = _balances[recipient].add(amount);
                                  emit Transfer(sender, recipient, amount);
                              }
                          
                              /** @dev Creates `amount` tokens and assigns them to `account`, increasing
                               * the total supply.
                               *
                               * Emits a {Transfer} event with `from` set to the zero address.
                               *
                               * Requirements
                               *
                               * - `to` cannot be the zero address.
                               */
                              function _mint(address account, uint256 amount) internal virtual {
                                  require(account != address(0), "ERC20: mint to the zero address");
                          
                                  _beforeTokenTransfer(address(0), account, amount);
                          
                                  _totalSupply = _totalSupply.add(amount);
                                  _balances[account] = _balances[account].add(amount);
                                  emit Transfer(address(0), account, amount);
                              }
                          
                              /**
                               * @dev Destroys `amount` tokens from `account`, reducing the
                               * total supply.
                               *
                               * Emits a {Transfer} event with `to` set to the zero address.
                               *
                               * Requirements
                               *
                               * - `account` cannot be the zero address.
                               * - `account` must have at least `amount` tokens.
                               */
                              function _burn(address account, uint256 amount) internal virtual {
                                  require(account != address(0), "ERC20: burn from the zero address");
                          
                                  _beforeTokenTransfer(account, address(0), amount);
                          
                                  _balances[account] = _balances[account].sub(amount, "ERC20: burn amount exceeds balance");
                                  _totalSupply = _totalSupply.sub(amount);
                                  emit Transfer(account, address(0), amount);
                              }
                          
                              /**
                               * @dev Sets `amount` as the allowance of `spender` over the `owner`s tokens.
                               *
                               * This is internal function is equivalent to `approve`, and can be used to
                               * e.g. set automatic allowances for certain subsystems, etc.
                               *
                               * Emits an {Approval} event.
                               *
                               * Requirements:
                               *
                               * - `owner` cannot be the zero address.
                               * - `spender` cannot be the zero address.
                               */
                              function _approve(address owner, address spender, uint256 amount) internal virtual {
                                  require(owner != address(0), "ERC20: approve from the zero address");
                                  require(spender != address(0), "ERC20: approve to the zero address");
                          
                                  _allowances[owner][spender] = amount;
                                  emit Approval(owner, spender, amount);
                              }
                          
                              /**
                               * @dev Sets {decimals} to a value other than the default one of 18.
                               *
                               * WARNING: This function should only be called from the constructor. Most
                               * applications that interact with token contracts will not expect
                               * {decimals} to ever change, and may work incorrectly if it does.
                               */
                              function _setupDecimals(uint8 decimals_) internal {
                                  _decimals = decimals_;
                              }
                          
                              /**
                               * @dev Hook that is called before any transfer of tokens. This includes
                               * minting and burning.
                               *
                               * Calling conditions:
                               *
                               * - when `from` and `to` are both non-zero, `amount` of ``from``'s tokens
                               * will be to transferred to `to`.
                               * - when `from` is zero, `amount` tokens will be minted for `to`.
                               * - when `to` is zero, `amount` of ``from``'s tokens will be burned.
                               * - `from` and `to` are never both zero.
                               *
                               * To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks].
                               */
                              function _beforeTokenTransfer(address from, address to, uint256 amount) internal virtual { }
                          }
                          
                          
                          /**
                           * @dev Contract module which allows children to implement an emergency stop
                           * mechanism that can be triggered by an authorized account.
                           *
                           * This module is used through inheritance. It will make available the
                           * modifiers `whenNotPaused` and `whenPaused`, which can be applied to
                           * the functions of your contract. Note that they will not be pausable by
                           * simply including this module, only once the modifiers are put in place.
                           */
                          contract Pausable is Context {
                              /**
                               * @dev Emitted when the pause is triggered by `account`.
                               */
                              event Paused(address account);
                          
                              /**
                               * @dev Emitted when the pause is lifted by `account`.
                               */
                              event Unpaused(address account);
                          
                              bool private _paused;
                          
                              /**
                               * @dev Initializes the contract in unpaused state.
                               */
                              constructor () internal {
                                  _paused = false;
                              }
                          
                              /**
                               * @dev Returns true if the contract is paused, and false otherwise.
                               */
                              function paused() public view returns (bool) {
                                  return _paused;
                              }
                          
                              /**
                               * @dev Modifier to make a function callable only when the contract is not paused.
                               */
                              modifier whenNotPaused() {
                                  require(!_paused, "Pausable: paused");
                                  _;
                              }
                          
                              /**
                               * @dev Modifier to make a function callable only when the contract is paused.
                               */
                              modifier whenPaused() {
                                  require(_paused, "Pausable: not paused");
                                  _;
                              }
                          
                              /**
                               * @dev Triggers stopped state.
                               */
                              function _pause() internal virtual whenNotPaused {
                                  _paused = true;
                                  emit Paused(_msgSender());
                              }
                          
                              /**
                               * @dev Returns to normal state.
                               */
                              function _unpause() internal virtual whenPaused {
                                  _paused = false;
                                  emit Unpaused(_msgSender());
                              }
                          }
                          
                          /**
                           * @dev ERC20 token with pausable token transfers, minting and burning.
                           *
                           * Useful for scenarios such as preventing trades until the end of an evaluation
                           * period, or having an emergency switch for freezing all token transfers in the
                           * event of a large bug.
                           */
                          abstract contract ERC20Pausable is ERC20, Pausable {
                              /**
                               * @dev See {ERC20-_beforeTokenTransfer}.
                               *
                               * Requirements:
                               *
                               * - the contract must not be paused.
                               */
                              function _beforeTokenTransfer(address from, address to, uint256 amount) internal virtual override {
                                  super._beforeTokenTransfer(from, to, amount);
                          
                                  require(!paused(), "ERC20Pausable: token transfer while paused");
                              }
                          }
                          
                          
                          /**
                           * @dev Extension of {ERC20} that allows token holders to destroy both their own
                           * tokens and those that they have an allowance for, in a way that can be
                           * recognized off-chain (via event analysis).
                           */
                          abstract contract ERC20Burnable is Context, ERC20 {
                              /**
                               * @dev Destroys `amount` tokens from the caller.
                               *
                               * See {ERC20-_burn}.
                               */
                              function burn(uint256 amount) external {
                                  _burn(_msgSender(), amount);
                              }
                          
                              /**
                               * @dev Destroys `amount` tokens from `account`, deducting from the caller's
                               * allowance.
                               *
                               * See {ERC20-_burn} and {ERC20-allowance}.
                               *
                               * Requirements:
                               *
                               * - the caller must have allowance for ``accounts``'s tokens of at least
                               * `amount`.
                               */
                              function burnFrom(address account, uint256 amount) external {
                                  uint256 decreasedAllowance = allowance(account, _msgSender()).sub(amount, "ERC20: burn amount exceeds allowance");
                          
                                  _approve(account, _msgSender(), decreasedAllowance);
                                  _burn(account, amount);
                              }
                          }
                          
                          /**
                           * @dev {ERC20} token, including:
                           *
                           *  - ability for holders to burn (destroy) their tokens
                           *  - a minter role that allows for token minting (creation)
                           *  - a pauser role that allows to stop all token transfers
                           *
                           * This contract uses {AccessControl} to lock permissioned functions using the
                           * different roles - head to its documentation for details.
                           *
                           * The account that deploys the contract will be granted the minter and pauser
                           * roles, as well as the default admin role, which will let it grant both minter
                           * and pauser roles to other accounts.
                           */
                          contract FetchToken is Context, AccessControl, ERC20Burnable, ERC20Pausable {
                              bytes32 public constant MINTER_ROLE = keccak256("MINTER_ROLE");
                              bytes32 public constant PAUSER_ROLE = keccak256("PAUSER_ROLE");
                          
                              /**
                               * @dev Grants `DEFAULT_ADMIN_ROLE`, `MINTER_ROLE` and `PAUSER_ROLE` to the
                               * account that deploys the contract.
                               *
                               * See {ERC20-constructor}.
                               */
                          
                          
                              modifier onlyMinter {
                                  require(hasRole(MINTER_ROLE, _msgSender()), "signer must have minter role to mint");
                                  _; 
                                  }
                          
                              modifier onlyPauser {
                                  require(hasRole(PAUSER_ROLE, _msgSender()), "signer must have pauser role to pause/unpause");
                                  _; 
                                  }
                          
                          
                              constructor(string memory name, 
                                          string memory symbol, 
                                          uint256 _initialSupply) public ERC20(name, symbol) {
                                  _setupRole(DEFAULT_ADMIN_ROLE, _msgSender());
                          
                                  _setupRole(MINTER_ROLE, _msgSender());
                                  _setupRole(PAUSER_ROLE, _msgSender());
                                  _mint(_msgSender(), _initialSupply); 
                              }
                          
                              /**
                               * @dev Creates `amount` new tokens for `to`.
                               *
                               * See {ERC20-_mint}.
                               *
                               * Requirements:
                               *
                               * - the caller must have the `MINTER_ROLE`.
                               */
                              function mint(address to, uint256 amount) onlyMinter external {
                                  _mint(to, amount);
                              }
                          
                              /**
                               * @dev Pauses all token transfers.
                               *
                               * See {ERC20Pausable} and {Pausable-_pause}.
                               *
                               * Requirements:
                               *
                               * - the caller must have the `PAUSER_ROLE`.
                               */
                              function pause() onlyPauser external {
                                  _pause();
                              }
                          
                              /**
                               * @dev Unpauses all token transfers.
                               *
                               * See {ERC20Pausable} and {Pausable-_unpause}.
                               *
                               * Requirements:
                               *
                               * - the caller must have the `PAUSER_ROLE`.
                               */
                              function unpause() onlyPauser external {
                                  _unpause();
                              }
                          
                              function _beforeTokenTransfer(address from, address to, uint256 amount) internal override(ERC20, ERC20Pausable) {
                                  super._beforeTokenTransfer(from, to, amount);
                              }
                          }

                          File 4 of 5: LayerZeroToken
                          // SPDX-License-Identifier: MIT
                          pragma solidity ^0.8.20;
                          // @dev Import the 'MessagingFee' and 'MessagingReceipt' so it's exposed to OApp implementers
                          // solhint-disable-next-line no-unused-import
                          import { OAppSender, MessagingFee, MessagingReceipt } from "./OAppSender.sol";
                          // @dev Import the 'Origin' so it's exposed to OApp implementers
                          // solhint-disable-next-line no-unused-import
                          import { OAppReceiver, Origin } from "./OAppReceiver.sol";
                          import { OAppCore } from "./OAppCore.sol";
                          /**
                           * @title OApp
                           * @dev Abstract contract serving as the base for OApp implementation, combining OAppSender and OAppReceiver functionality.
                           */
                          abstract contract OApp is OAppSender, OAppReceiver {
                              /**
                               * @dev Constructor to initialize the OApp with the provided endpoint and owner.
                               * @param _endpoint The address of the LOCAL LayerZero endpoint.
                               * @param _delegate The delegate capable of making OApp configurations inside of the endpoint.
                               */
                              constructor(address _endpoint, address _delegate) OAppCore(_endpoint, _delegate) {}
                              /**
                               * @notice Retrieves the OApp version information.
                               * @return senderVersion The version of the OAppSender.sol implementation.
                               * @return receiverVersion The version of the OAppReceiver.sol implementation.
                               */
                              function oAppVersion()
                                  public
                                  pure
                                  virtual
                                  override(OAppSender, OAppReceiver)
                                  returns (uint64 senderVersion, uint64 receiverVersion)
                              {
                                  return (SENDER_VERSION, RECEIVER_VERSION);
                              }
                          }
                          // SPDX-License-Identifier: MIT
                          pragma solidity ^0.8.20;
                          import { Ownable } from "@openzeppelin/contracts/access/Ownable.sol";
                          import { IOAppCore, ILayerZeroEndpointV2 } from "./interfaces/IOAppCore.sol";
                          /**
                           * @title OAppCore
                           * @dev Abstract contract implementing the IOAppCore interface with basic OApp configurations.
                           */
                          abstract contract OAppCore is IOAppCore, Ownable {
                              // The LayerZero endpoint associated with the given OApp
                              ILayerZeroEndpointV2 public immutable endpoint;
                              // Mapping to store peers associated with corresponding endpoints
                              mapping(uint32 eid => bytes32 peer) public peers;
                              /**
                               * @dev Constructor to initialize the OAppCore with the provided endpoint and delegate.
                               * @param _endpoint The address of the LOCAL Layer Zero endpoint.
                               * @param _delegate The delegate capable of making OApp configurations inside of the endpoint.
                               *
                               * @dev The delegate typically should be set as the owner of the contract.
                               */
                              constructor(address _endpoint, address _delegate) {
                                  endpoint = ILayerZeroEndpointV2(_endpoint);
                                  if (_delegate == address(0)) revert InvalidDelegate();
                                  endpoint.setDelegate(_delegate);
                              }
                              /**
                               * @notice Sets the peer address (OApp instance) for a corresponding endpoint.
                               * @param _eid The endpoint ID.
                               * @param _peer The address of the peer to be associated with the corresponding endpoint.
                               *
                               * @dev Only the owner/admin of the OApp can call this function.
                               * @dev Indicates that the peer is trusted to send LayerZero messages to this OApp.
                               * @dev Set this to bytes32(0) to remove the peer address.
                               * @dev Peer is a bytes32 to accommodate non-evm chains.
                               */
                              function setPeer(uint32 _eid, bytes32 _peer) public virtual onlyOwner {
                                  _setPeer(_eid, _peer);
                              }
                              /**
                               * @notice Sets the peer address (OApp instance) for a corresponding endpoint.
                               * @param _eid The endpoint ID.
                               * @param _peer The address of the peer to be associated with the corresponding endpoint.
                               *
                               * @dev Indicates that the peer is trusted to send LayerZero messages to this OApp.
                               * @dev Set this to bytes32(0) to remove the peer address.
                               * @dev Peer is a bytes32 to accommodate non-evm chains.
                               */
                              function _setPeer(uint32 _eid, bytes32 _peer) internal virtual {
                                  peers[_eid] = _peer;
                                  emit PeerSet(_eid, _peer);
                              }
                              /**
                               * @notice Internal function to get the peer address associated with a specific endpoint; reverts if NOT set.
                               * ie. the peer is set to bytes32(0).
                               * @param _eid The endpoint ID.
                               * @return peer The address of the peer associated with the specified endpoint.
                               */
                              function _getPeerOrRevert(uint32 _eid) internal view virtual returns (bytes32) {
                                  bytes32 peer = peers[_eid];
                                  if (peer == bytes32(0)) revert NoPeer(_eid);
                                  return peer;
                              }
                              /**
                               * @notice Sets the delegate address for the OApp.
                               * @param _delegate The address of the delegate to be set.
                               *
                               * @dev Only the owner/admin of the OApp can call this function.
                               * @dev Provides the ability for a delegate to set configs, on behalf of the OApp, directly on the Endpoint contract.
                               */
                              function setDelegate(address _delegate) public onlyOwner {
                                  endpoint.setDelegate(_delegate);
                              }
                          }
                          // SPDX-License-Identifier: MIT
                          pragma solidity ^0.8.20;
                          import { IOAppReceiver, Origin } from "./interfaces/IOAppReceiver.sol";
                          import { OAppCore } from "./OAppCore.sol";
                          /**
                           * @title OAppReceiver
                           * @dev Abstract contract implementing the ILayerZeroReceiver interface and extending OAppCore for OApp receivers.
                           */
                          abstract contract OAppReceiver is IOAppReceiver, OAppCore {
                              // Custom error message for when the caller is not the registered endpoint/
                              error OnlyEndpoint(address addr);
                              // @dev The version of the OAppReceiver implementation.
                              // @dev Version is bumped when changes are made to this contract.
                              uint64 internal constant RECEIVER_VERSION = 2;
                              /**
                               * @notice Retrieves the OApp version information.
                               * @return senderVersion The version of the OAppSender.sol contract.
                               * @return receiverVersion The version of the OAppReceiver.sol contract.
                               *
                               * @dev Providing 0 as the default for OAppSender version. Indicates that the OAppSender is not implemented.
                               * ie. this is a RECEIVE only OApp.
                               * @dev If the OApp uses both OAppSender and OAppReceiver, then this needs to be override returning the correct versions.
                               */
                              function oAppVersion() public view virtual returns (uint64 senderVersion, uint64 receiverVersion) {
                                  return (0, RECEIVER_VERSION);
                              }
                              /**
                               * @notice Indicates whether an address is an approved composeMsg sender to the Endpoint.
                               * @dev _origin The origin information containing the source endpoint and sender address.
                               *  - srcEid: The source chain endpoint ID.
                               *  - sender: The sender address on the src chain.
                               *  - nonce: The nonce of the message.
                               * @dev _message The lzReceive payload.
                               * @param _sender The sender address.
                               * @return isSender Is a valid sender.
                               *
                               * @dev Applications can optionally choose to implement separate composeMsg senders that are NOT the bridging layer.
                               * @dev The default sender IS the OAppReceiver implementer.
                               */
                              function isComposeMsgSender(
                                  Origin calldata /*_origin*/,
                                  bytes calldata /*_message*/,
                                  address _sender
                              ) public view virtual returns (bool) {
                                  return _sender == address(this);
                              }
                              /**
                               * @notice Checks if the path initialization is allowed based on the provided origin.
                               * @param origin The origin information containing the source endpoint and sender address.
                               * @return Whether the path has been initialized.
                               *
                               * @dev This indicates to the endpoint that the OApp has enabled msgs for this particular path to be received.
                               * @dev This defaults to assuming if a peer has been set, its initialized.
                               * Can be overridden by the OApp if there is other logic to determine this.
                               */
                              function allowInitializePath(Origin calldata origin) public view virtual returns (bool) {
                                  return peers[origin.srcEid] == origin.sender;
                              }
                              /**
                               * @notice Retrieves the next nonce for a given source endpoint and sender address.
                               * @dev _srcEid The source endpoint ID.
                               * @dev _sender The sender address.
                               * @return nonce The next nonce.
                               *
                               * @dev The path nonce starts from 1. If 0 is returned it means that there is NO nonce ordered enforcement.
                               * @dev Is required by the off-chain executor to determine the OApp expects msg execution is ordered.
                               * @dev This is also enforced by the OApp.
                               * @dev By default this is NOT enabled. ie. nextNonce is hardcoded to return 0.
                               */
                              function nextNonce(uint32 /*_srcEid*/, bytes32 /*_sender*/) public view virtual returns (uint64 nonce) {
                                  return 0;
                              }
                              /**
                               * @dev Entry point for receiving messages or packets from the endpoint.
                               * @param _origin The origin information containing the source endpoint and sender address.
                               *  - srcEid: The source chain endpoint ID.
                               *  - sender: The sender address on the src chain.
                               *  - nonce: The nonce of the message.
                               * @param _guid The unique identifier for the received LayerZero message.
                               * @param _message The payload of the received message.
                               * @param _executor The address of the executor for the received message.
                               * @param _extraData Additional arbitrary data provided by the corresponding executor.
                               *
                               * @dev Entry point for receiving msg/packet from the LayerZero endpoint.
                               */
                              function lzReceive(
                                  Origin calldata _origin,
                                  bytes32 _guid,
                                  bytes calldata _message,
                                  address _executor,
                                  bytes calldata _extraData
                              ) public payable virtual {
                                  // Ensures that only the endpoint can attempt to lzReceive() messages to this OApp.
                                  if (address(endpoint) != msg.sender) revert OnlyEndpoint(msg.sender);
                                  // Ensure that the sender matches the expected peer for the source endpoint.
                                  if (_getPeerOrRevert(_origin.srcEid) != _origin.sender) revert OnlyPeer(_origin.srcEid, _origin.sender);
                                  // Call the internal OApp implementation of lzReceive.
                                  _lzReceive(_origin, _guid, _message, _executor, _extraData);
                              }
                              /**
                               * @dev Internal function to implement lzReceive logic without needing to copy the basic parameter validation.
                               */
                              function _lzReceive(
                                  Origin calldata _origin,
                                  bytes32 _guid,
                                  bytes calldata _message,
                                  address _executor,
                                  bytes calldata _extraData
                              ) internal virtual;
                          }
                          // SPDX-License-Identifier: MIT
                          pragma solidity ^0.8.20;
                          import { SafeERC20, IERC20 } from "@openzeppelin/contracts/token/ERC20/utils/SafeERC20.sol";
                          import { MessagingParams, MessagingFee, MessagingReceipt } from "@layerzerolabs/lz-evm-protocol-v2/contracts/interfaces/ILayerZeroEndpointV2.sol";
                          import { OAppCore } from "./OAppCore.sol";
                          /**
                           * @title OAppSender
                           * @dev Abstract contract implementing the OAppSender functionality for sending messages to a LayerZero endpoint.
                           */
                          abstract contract OAppSender is OAppCore {
                              using SafeERC20 for IERC20;
                              // Custom error messages
                              error NotEnoughNative(uint256 msgValue);
                              error LzTokenUnavailable();
                              // @dev The version of the OAppSender implementation.
                              // @dev Version is bumped when changes are made to this contract.
                              uint64 internal constant SENDER_VERSION = 1;
                              /**
                               * @notice Retrieves the OApp version information.
                               * @return senderVersion The version of the OAppSender.sol contract.
                               * @return receiverVersion The version of the OAppReceiver.sol contract.
                               *
                               * @dev Providing 0 as the default for OAppReceiver version. Indicates that the OAppReceiver is not implemented.
                               * ie. this is a SEND only OApp.
                               * @dev If the OApp uses both OAppSender and OAppReceiver, then this needs to be override returning the correct versions
                               */
                              function oAppVersion() public view virtual returns (uint64 senderVersion, uint64 receiverVersion) {
                                  return (SENDER_VERSION, 0);
                              }
                              /**
                               * @dev Internal function to interact with the LayerZero EndpointV2.quote() for fee calculation.
                               * @param _dstEid The destination endpoint ID.
                               * @param _message The message payload.
                               * @param _options Additional options for the message.
                               * @param _payInLzToken Flag indicating whether to pay the fee in LZ tokens.
                               * @return fee The calculated MessagingFee for the message.
                               *      - nativeFee: The native fee for the message.
                               *      - lzTokenFee: The LZ token fee for the message.
                               */
                              function _quote(
                                  uint32 _dstEid,
                                  bytes memory _message,
                                  bytes memory _options,
                                  bool _payInLzToken
                              ) internal view virtual returns (MessagingFee memory fee) {
                                  return
                                      endpoint.quote(
                                          MessagingParams(_dstEid, _getPeerOrRevert(_dstEid), _message, _options, _payInLzToken),
                                          address(this)
                                      );
                              }
                              /**
                               * @dev Internal function to interact with the LayerZero EndpointV2.send() for sending a message.
                               * @param _dstEid The destination endpoint ID.
                               * @param _message The message payload.
                               * @param _options Additional options for the message.
                               * @param _fee The calculated LayerZero fee for the message.
                               *      - nativeFee: The native fee.
                               *      - lzTokenFee: The lzToken fee.
                               * @param _refundAddress The address to receive any excess fee values sent to the endpoint.
                               * @return receipt The receipt for the sent message.
                               *      - guid: The unique identifier for the sent message.
                               *      - nonce: The nonce of the sent message.
                               *      - fee: The LayerZero fee incurred for the message.
                               */
                              function _lzSend(
                                  uint32 _dstEid,
                                  bytes memory _message,
                                  bytes memory _options,
                                  MessagingFee memory _fee,
                                  address _refundAddress
                              ) internal virtual returns (MessagingReceipt memory receipt) {
                                  // @dev Push corresponding fees to the endpoint, any excess is sent back to the _refundAddress from the endpoint.
                                  uint256 messageValue = _payNative(_fee.nativeFee);
                                  if (_fee.lzTokenFee > 0) _payLzToken(_fee.lzTokenFee);
                                  return
                                      // solhint-disable-next-line check-send-result
                                      endpoint.send{ value: messageValue }(
                                          MessagingParams(_dstEid, _getPeerOrRevert(_dstEid), _message, _options, _fee.lzTokenFee > 0),
                                          _refundAddress
                                      );
                              }
                              /**
                               * @dev Internal function to pay the native fee associated with the message.
                               * @param _nativeFee The native fee to be paid.
                               * @return nativeFee The amount of native currency paid.
                               *
                               * @dev If the OApp needs to initiate MULTIPLE LayerZero messages in a single transaction,
                               * this will need to be overridden because msg.value would contain multiple lzFees.
                               * @dev Should be overridden in the event the LayerZero endpoint requires a different native currency.
                               * @dev Some EVMs use an ERC20 as a method for paying transactions/gasFees.
                               * @dev The endpoint is EITHER/OR, ie. it will NOT support both types of native payment at a time.
                               */
                              function _payNative(uint256 _nativeFee) internal virtual returns (uint256 nativeFee) {
                                  if (msg.value != _nativeFee) revert NotEnoughNative(msg.value);
                                  return _nativeFee;
                              }
                              /**
                               * @dev Internal function to pay the LZ token fee associated with the message.
                               * @param _lzTokenFee The LZ token fee to be paid.
                               *
                               * @dev If the caller is trying to pay in the specified lzToken, then the lzTokenFee is passed to the endpoint.
                               * @dev Any excess sent, is passed back to the specified _refundAddress in the _lzSend().
                               */
                              function _payLzToken(uint256 _lzTokenFee) internal virtual {
                                  // @dev Cannot cache the token because it is not immutable in the endpoint.
                                  address lzToken = endpoint.lzToken();
                                  if (lzToken == address(0)) revert LzTokenUnavailable();
                                  // Pay LZ token fee by sending tokens to the endpoint.
                                  IERC20(lzToken).safeTransferFrom(msg.sender, address(endpoint), _lzTokenFee);
                              }
                          }
                          // SPDX-License-Identifier: MIT
                          pragma solidity ^0.8.20;
                          import { ILayerZeroEndpointV2 } from "@layerzerolabs/lz-evm-protocol-v2/contracts/interfaces/ILayerZeroEndpointV2.sol";
                          /**
                           * @title IOAppCore
                           */
                          interface IOAppCore {
                              // Custom error messages
                              error OnlyPeer(uint32 eid, bytes32 sender);
                              error NoPeer(uint32 eid);
                              error InvalidEndpointCall();
                              error InvalidDelegate();
                              // Event emitted when a peer (OApp) is set for a corresponding endpoint
                              event PeerSet(uint32 eid, bytes32 peer);
                              /**
                               * @notice Retrieves the OApp version information.
                               * @return senderVersion The version of the OAppSender.sol contract.
                               * @return receiverVersion The version of the OAppReceiver.sol contract.
                               */
                              function oAppVersion() external view returns (uint64 senderVersion, uint64 receiverVersion);
                              /**
                               * @notice Retrieves the LayerZero endpoint associated with the OApp.
                               * @return iEndpoint The LayerZero endpoint as an interface.
                               */
                              function endpoint() external view returns (ILayerZeroEndpointV2 iEndpoint);
                              /**
                               * @notice Retrieves the peer (OApp) associated with a corresponding endpoint.
                               * @param _eid The endpoint ID.
                               * @return peer The peer address (OApp instance) associated with the corresponding endpoint.
                               */
                              function peers(uint32 _eid) external view returns (bytes32 peer);
                              /**
                               * @notice Sets the peer address (OApp instance) for a corresponding endpoint.
                               * @param _eid The endpoint ID.
                               * @param _peer The address of the peer to be associated with the corresponding endpoint.
                               */
                              function setPeer(uint32 _eid, bytes32 _peer) external;
                              /**
                               * @notice Sets the delegate address for the OApp Core.
                               * @param _delegate The address of the delegate to be set.
                               */
                              function setDelegate(address _delegate) external;
                          }
                          // SPDX-License-Identifier: MIT
                          pragma solidity ^0.8.20;
                          /**
                           * @title IOAppMsgInspector
                           * @dev Interface for the OApp Message Inspector, allowing examination of message and options contents.
                           */
                          interface IOAppMsgInspector {
                              // Custom error message for inspection failure
                              error InspectionFailed(bytes message, bytes options);
                              /**
                               * @notice Allows the inspector to examine LayerZero message contents and optionally throw a revert if invalid.
                               * @param _message The message payload to be inspected.
                               * @param _options Additional options or parameters for inspection.
                               * @return valid A boolean indicating whether the inspection passed (true) or failed (false).
                               *
                               * @dev Optionally done as a revert, OR use the boolean provided to handle the failure.
                               */
                              function inspect(bytes calldata _message, bytes calldata _options) external view returns (bool valid);
                          }
                          // SPDX-License-Identifier: MIT
                          pragma solidity ^0.8.20;
                          /**
                           * @dev Struct representing enforced option parameters.
                           */
                          struct EnforcedOptionParam {
                              uint32 eid; // Endpoint ID
                              uint16 msgType; // Message Type
                              bytes options; // Additional options
                          }
                          /**
                           * @title IOAppOptionsType3
                           * @dev Interface for the OApp with Type 3 Options, allowing the setting and combining of enforced options.
                           */
                          interface IOAppOptionsType3 {
                              // Custom error message for invalid options
                              error InvalidOptions(bytes options);
                              // Event emitted when enforced options are set
                              event EnforcedOptionSet(EnforcedOptionParam[] _enforcedOptions);
                              /**
                               * @notice Sets enforced options for specific endpoint and message type combinations.
                               * @param _enforcedOptions An array of EnforcedOptionParam structures specifying enforced options.
                               */
                              function setEnforcedOptions(EnforcedOptionParam[] calldata _enforcedOptions) external;
                              /**
                               * @notice Combines options for a given endpoint and message type.
                               * @param _eid The endpoint ID.
                               * @param _msgType The OApp message type.
                               * @param _extraOptions Additional options passed by the caller.
                               * @return options The combination of caller specified options AND enforced options.
                               */
                              function combineOptions(
                                  uint32 _eid,
                                  uint16 _msgType,
                                  bytes calldata _extraOptions
                              ) external view returns (bytes memory options);
                          }
                          // SPDX-License-Identifier: MIT
                          pragma solidity ^0.8.20;
                          import { ILayerZeroReceiver, Origin } from "@layerzerolabs/lz-evm-protocol-v2/contracts/interfaces/ILayerZeroReceiver.sol";
                          interface IOAppReceiver is ILayerZeroReceiver {
                              /**
                               * @notice Indicates whether an address is an approved composeMsg sender to the Endpoint.
                               * @param _origin The origin information containing the source endpoint and sender address.
                               *  - srcEid: The source chain endpoint ID.
                               *  - sender: The sender address on the src chain.
                               *  - nonce: The nonce of the message.
                               * @param _message The lzReceive payload.
                               * @param _sender The sender address.
                               * @return isSender Is a valid sender.
                               *
                               * @dev Applications can optionally choose to implement a separate composeMsg sender that is NOT the bridging layer.
                               * @dev The default sender IS the OAppReceiver implementer.
                               */
                              function isComposeMsgSender(
                                  Origin calldata _origin,
                                  bytes calldata _message,
                                  address _sender
                              ) external view returns (bool isSender);
                          }
                          // SPDX-License-Identifier: MIT
                          pragma solidity ^0.8.20;
                          import { Ownable } from "@openzeppelin/contracts/access/Ownable.sol";
                          import { IOAppOptionsType3, EnforcedOptionParam } from "../interfaces/IOAppOptionsType3.sol";
                          /**
                           * @title OAppOptionsType3
                           * @dev Abstract contract implementing the IOAppOptionsType3 interface with type 3 options.
                           */
                          abstract contract OAppOptionsType3 is IOAppOptionsType3, Ownable {
                              uint16 internal constant OPTION_TYPE_3 = 3;
                              // @dev The "msgType" should be defined in the child contract.
                              mapping(uint32 eid => mapping(uint16 msgType => bytes enforcedOption)) public enforcedOptions;
                              /**
                               * @dev Sets the enforced options for specific endpoint and message type combinations.
                               * @param _enforcedOptions An array of EnforcedOptionParam structures specifying enforced options.
                               *
                               * @dev Only the owner/admin of the OApp can call this function.
                               * @dev Provides a way for the OApp to enforce things like paying for PreCrime, AND/OR minimum dst lzReceive gas amounts etc.
                               * @dev These enforced options can vary as the potential options/execution on the remote may differ as per the msgType.
                               * eg. Amount of lzReceive() gas necessary to deliver a lzCompose() message adds overhead you dont want to pay
                               * if you are only making a standard LayerZero message ie. lzReceive() WITHOUT sendCompose().
                               */
                              function setEnforcedOptions(EnforcedOptionParam[] calldata _enforcedOptions) public virtual onlyOwner {
                                  _setEnforcedOptions(_enforcedOptions);
                              }
                              /**
                               * @dev Sets the enforced options for specific endpoint and message type combinations.
                               * @param _enforcedOptions An array of EnforcedOptionParam structures specifying enforced options.
                               *
                               * @dev Provides a way for the OApp to enforce things like paying for PreCrime, AND/OR minimum dst lzReceive gas amounts etc.
                               * @dev These enforced options can vary as the potential options/execution on the remote may differ as per the msgType.
                               * eg. Amount of lzReceive() gas necessary to deliver a lzCompose() message adds overhead you dont want to pay
                               * if you are only making a standard LayerZero message ie. lzReceive() WITHOUT sendCompose().
                               */
                              function _setEnforcedOptions(EnforcedOptionParam[] calldata _enforcedOptions) internal virtual {
                                  for (uint256 i = 0; i < _enforcedOptions.length; i++) {
                                      // @dev Enforced options are only available for optionType 3, as type 1 and 2 dont support combining.
                                      _assertOptionsType3(_enforcedOptions[i].options);
                                      enforcedOptions[_enforcedOptions[i].eid][_enforcedOptions[i].msgType] = _enforcedOptions[i].options;
                                  }
                                  emit EnforcedOptionSet(_enforcedOptions);
                              }
                              /**
                               * @notice Combines options for a given endpoint and message type.
                               * @param _eid The endpoint ID.
                               * @param _msgType The OAPP message type.
                               * @param _extraOptions Additional options passed by the caller.
                               * @return options The combination of caller specified options AND enforced options.
                               *
                               * @dev If there is an enforced lzReceive option:
                               * - {gasLimit: 200k, msg.value: 1 ether} AND a caller supplies a lzReceive option: {gasLimit: 100k, msg.value: 0.5 ether}
                               * - The resulting options will be {gasLimit: 300k, msg.value: 1.5 ether} when the message is executed on the remote lzReceive() function.
                               * @dev This presence of duplicated options is handled off-chain in the verifier/executor.
                               */
                              function combineOptions(
                                  uint32 _eid,
                                  uint16 _msgType,
                                  bytes calldata _extraOptions
                              ) public view virtual returns (bytes memory) {
                                  bytes memory enforced = enforcedOptions[_eid][_msgType];
                                  // No enforced options, pass whatever the caller supplied, even if it's empty or legacy type 1/2 options.
                                  if (enforced.length == 0) return _extraOptions;
                                  // No caller options, return enforced
                                  if (_extraOptions.length == 0) return enforced;
                                  // @dev If caller provided _extraOptions, must be type 3 as its the ONLY type that can be combined.
                                  if (_extraOptions.length >= 2) {
                                      _assertOptionsType3(_extraOptions);
                                      // @dev Remove the first 2 bytes containing the type from the _extraOptions and combine with enforced.
                                      return bytes.concat(enforced, _extraOptions[2:]);
                                  }
                                  // No valid set of options was found.
                                  revert InvalidOptions(_extraOptions);
                              }
                              /**
                               * @dev Internal function to assert that options are of type 3.
                               * @param _options The options to be checked.
                               */
                              function _assertOptionsType3(bytes calldata _options) internal pure virtual {
                                  uint16 optionsType = uint16(bytes2(_options[0:2]));
                                  if (optionsType != OPTION_TYPE_3) revert InvalidOptions(_options);
                              }
                          }
                          // SPDX-License-Identifier: MIT
                          pragma solidity ^0.8.20;
                          import { ERC20 } from "@openzeppelin/contracts/token/ERC20/ERC20.sol";
                          import { IOFT, OFTCore } from "./OFTCore.sol";
                          /**
                           * @title OFT Contract
                           * @dev OFT is an ERC-20 token that extends the functionality of the OFTCore contract.
                           */
                          abstract contract OFT is OFTCore, ERC20 {
                              /**
                               * @dev Constructor for the OFT contract.
                               * @param _name The name of the OFT.
                               * @param _symbol The symbol of the OFT.
                               * @param _lzEndpoint The LayerZero endpoint address.
                               * @param _delegate The delegate capable of making OApp configurations inside of the endpoint.
                               */
                              constructor(
                                  string memory _name,
                                  string memory _symbol,
                                  address _lzEndpoint,
                                  address _delegate
                              ) ERC20(_name, _symbol) OFTCore(decimals(), _lzEndpoint, _delegate) {}
                              /**
                               * @dev Retrieves the address of the underlying ERC20 implementation.
                               * @return The address of the OFT token.
                               *
                               * @dev In the case of OFT, address(this) and erc20 are the same contract.
                               */
                              function token() public view returns (address) {
                                  return address(this);
                              }
                              /**
                               * @notice Indicates whether the OFT contract requires approval of the 'token()' to send.
                               * @return requiresApproval Needs approval of the underlying token implementation.
                               *
                               * @dev In the case of OFT where the contract IS the token, approval is NOT required.
                               */
                              function approvalRequired() external pure virtual returns (bool) {
                                  return false;
                              }
                              /**
                               * @dev Burns tokens from the sender's specified balance.
                               * @param _from The address to debit the tokens from.
                               * @param _amountLD The amount of tokens to send in local decimals.
                               * @param _minAmountLD The minimum amount to send in local decimals.
                               * @param _dstEid The destination chain ID.
                               * @return amountSentLD The amount sent in local decimals.
                               * @return amountReceivedLD The amount received in local decimals on the remote.
                               */
                              function _debit(
                                  address _from,
                                  uint256 _amountLD,
                                  uint256 _minAmountLD,
                                  uint32 _dstEid
                              ) internal virtual override returns (uint256 amountSentLD, uint256 amountReceivedLD) {
                                  (amountSentLD, amountReceivedLD) = _debitView(_amountLD, _minAmountLD, _dstEid);
                                  // @dev In NON-default OFT, amountSentLD could be 100, with a 10% fee, the amountReceivedLD amount is 90,
                                  // therefore amountSentLD CAN differ from amountReceivedLD.
                                  // @dev Default OFT burns on src.
                                  _burn(_from, amountSentLD);
                              }
                              /**
                               * @dev Credits tokens to the specified address.
                               * @param _to The address to credit the tokens to.
                               * @param _amountLD The amount of tokens to credit in local decimals.
                               * @dev _srcEid The source chain ID.
                               * @return amountReceivedLD The amount of tokens ACTUALLY received in local decimals.
                               */
                              function _credit(
                                  address _to,
                                  uint256 _amountLD,
                                  uint32 /*_srcEid*/
                              ) internal virtual override returns (uint256 amountReceivedLD) {
                                  // @dev Default OFT mints on dst.
                                  _mint(_to, _amountLD);
                                  // @dev In the case of NON-default OFT, the _amountLD MIGHT not be == amountReceivedLD.
                                  return _amountLD;
                              }
                          }
                          // SPDX-License-Identifier: MIT
                          pragma solidity ^0.8.20;
                          import { OApp, Origin } from "../oapp/OApp.sol";
                          import { OAppOptionsType3 } from "../oapp/libs/OAppOptionsType3.sol";
                          import { IOAppMsgInspector } from "../oapp/interfaces/IOAppMsgInspector.sol";
                          import { OAppPreCrimeSimulator } from "../precrime/OAppPreCrimeSimulator.sol";
                          import { IOFT, SendParam, OFTLimit, OFTReceipt, OFTFeeDetail, MessagingReceipt, MessagingFee } from "./interfaces/IOFT.sol";
                          import { OFTMsgCodec } from "./libs/OFTMsgCodec.sol";
                          import { OFTComposeMsgCodec } from "./libs/OFTComposeMsgCodec.sol";
                          /**
                           * @title OFTCore
                           * @dev Abstract contract for the OftChain (OFT) token.
                           */
                          abstract contract OFTCore is IOFT, OApp, OAppPreCrimeSimulator, OAppOptionsType3 {
                              using OFTMsgCodec for bytes;
                              using OFTMsgCodec for bytes32;
                              // @notice Provides a conversion rate when swapping between denominations of SD and LD
                              //      - shareDecimals == SD == shared Decimals
                              //      - localDecimals == LD == local decimals
                              // @dev Considers that tokens have different decimal amounts on various chains.
                              // @dev eg.
                              //  For a token
                              //      - locally with 4 decimals --> 1.2345 => uint(12345)
                              //      - remotely with 2 decimals --> 1.23 => uint(123)
                              //      - The conversion rate would be 10 ** (4 - 2) = 100
                              //  @dev If you want to send 1.2345 -> (uint 12345), you CANNOT represent that value on the remote,
                              //  you can only display 1.23 -> uint(123).
                              //  @dev To preserve the dust that would otherwise be lost on that conversion,
                              //  we need to unify a denomination that can be represented on ALL chains inside of the OFT mesh
                              uint256 public immutable decimalConversionRate;
                              // @notice Msg types that are used to identify the various OFT operations.
                              // @dev This can be extended in child contracts for non-default oft operations
                              // @dev These values are used in things like combineOptions() in OAppOptionsType3.sol.
                              uint16 public constant SEND = 1;
                              uint16 public constant SEND_AND_CALL = 2;
                              // Address of an optional contract to inspect both 'message' and 'options'
                              address public msgInspector;
                              event MsgInspectorSet(address inspector);
                              /**
                               * @dev Constructor.
                               * @param _localDecimals The decimals of the token on the local chain (this chain).
                               * @param _endpoint The address of the LayerZero endpoint.
                               * @param _delegate The delegate capable of making OApp configurations inside of the endpoint.
                               */
                              constructor(uint8 _localDecimals, address _endpoint, address _delegate) OApp(_endpoint, _delegate) {
                                  if (_localDecimals < sharedDecimals()) revert InvalidLocalDecimals();
                                  decimalConversionRate = 10 ** (_localDecimals - sharedDecimals());
                              }
                              /**
                               * @notice Retrieves interfaceID and the version of the OFT.
                               * @return interfaceId The interface ID.
                               * @return version The version.
                               *
                               * @dev interfaceId: This specific interface ID is '0x02e49c2c'.
                               * @dev version: Indicates a cross-chain compatible msg encoding with other OFTs.
                               * @dev If a new feature is added to the OFT cross-chain msg encoding, the version will be incremented.
                               * ie. localOFT version(x,1) CAN send messages to remoteOFT version(x,1)
                               */
                              function oftVersion() external pure virtual returns (bytes4 interfaceId, uint64 version) {
                                  return (type(IOFT).interfaceId, 1);
                              }
                              /**
                               * @dev Retrieves the shared decimals of the OFT.
                               * @return The shared decimals of the OFT.
                               *
                               * @dev Sets an implicit cap on the amount of tokens, over uint64.max() will need some sort of outbound cap / totalSupply cap
                               * Lowest common decimal denominator between chains.
                               * Defaults to 6 decimal places to provide up to 18,446,744,073,709.551615 units (max uint64).
                               * For tokens exceeding this totalSupply(), they will need to override the sharedDecimals function with something smaller.
                               * ie. 4 sharedDecimals would be 1,844,674,407,370,955.1615
                               */
                              function sharedDecimals() public pure virtual returns (uint8) {
                                  return 6;
                              }
                              /**
                               * @dev Sets the message inspector address for the OFT.
                               * @param _msgInspector The address of the message inspector.
                               *
                               * @dev This is an optional contract that can be used to inspect both 'message' and 'options'.
                               * @dev Set it to address(0) to disable it, or set it to a contract address to enable it.
                               */
                              function setMsgInspector(address _msgInspector) public virtual onlyOwner {
                                  msgInspector = _msgInspector;
                                  emit MsgInspectorSet(_msgInspector);
                              }
                              /**
                               * @notice Provides a quote for OFT-related operations.
                               * @param _sendParam The parameters for the send operation.
                               * @return oftLimit The OFT limit information.
                               * @return oftFeeDetails The details of OFT fees.
                               * @return oftReceipt The OFT receipt information.
                               */
                              function quoteOFT(
                                  SendParam calldata _sendParam
                              )
                                  external
                                  view
                                  virtual
                                  returns (OFTLimit memory oftLimit, OFTFeeDetail[] memory oftFeeDetails, OFTReceipt memory oftReceipt)
                              {
                                  uint256 minAmountLD = 0; // Unused in the default implementation.
                                  uint256 maxAmountLD = type(uint64).max; // Unused in the default implementation.
                                  oftLimit = OFTLimit(minAmountLD, maxAmountLD);
                                  // Unused in the default implementation; reserved for future complex fee details.
                                  oftFeeDetails = new OFTFeeDetail[](0);
                                  // @dev This is the same as the send() operation, but without the actual send.
                                  // - amountSentLD is the amount in local decimals that would be sent from the sender.
                                  // - amountReceivedLD is the amount in local decimals that will be credited to the recipient on the remote OFT instance.
                                  // @dev The amountSentLD MIGHT not equal the amount the user actually receives. HOWEVER, the default does.
                                  (uint256 amountSentLD, uint256 amountReceivedLD) = _debitView(
                                      _sendParam.amountLD,
                                      _sendParam.minAmountLD,
                                      _sendParam.dstEid
                                  );
                                  oftReceipt = OFTReceipt(amountSentLD, amountReceivedLD);
                              }
                              /**
                               * @notice Provides a quote for the send() operation.
                               * @param _sendParam The parameters for the send() operation.
                               * @param _payInLzToken Flag indicating whether the caller is paying in the LZ token.
                               * @return msgFee The calculated LayerZero messaging fee from the send() operation.
                               *
                               * @dev MessagingFee: LayerZero msg fee
                               *  - nativeFee: The native fee.
                               *  - lzTokenFee: The lzToken fee.
                               */
                              function quoteSend(
                                  SendParam calldata _sendParam,
                                  bool _payInLzToken
                              ) external view virtual returns (MessagingFee memory msgFee) {
                                  // @dev mock the amount to receive, this is the same operation used in the send().
                                  // The quote is as similar as possible to the actual send() operation.
                                  (, uint256 amountReceivedLD) = _debitView(_sendParam.amountLD, _sendParam.minAmountLD, _sendParam.dstEid);
                                  // @dev Builds the options and OFT message to quote in the endpoint.
                                  (bytes memory message, bytes memory options) = _buildMsgAndOptions(_sendParam, amountReceivedLD);
                                  // @dev Calculates the LayerZero fee for the send() operation.
                                  return _quote(_sendParam.dstEid, message, options, _payInLzToken);
                              }
                              /**
                               * @dev Executes the send operation.
                               * @param _sendParam The parameters for the send operation.
                               * @param _fee The calculated fee for the send() operation.
                               *      - nativeFee: The native fee.
                               *      - lzTokenFee: The lzToken fee.
                               * @param _refundAddress The address to receive any excess funds.
                               * @return msgReceipt The receipt for the send operation.
                               * @return oftReceipt The OFT receipt information.
                               *
                               * @dev MessagingReceipt: LayerZero msg receipt
                               *  - guid: The unique identifier for the sent message.
                               *  - nonce: The nonce of the sent message.
                               *  - fee: The LayerZero fee incurred for the message.
                               */
                              function send(
                                  SendParam calldata _sendParam,
                                  MessagingFee calldata _fee,
                                  address _refundAddress
                              ) external payable virtual returns (MessagingReceipt memory msgReceipt, OFTReceipt memory oftReceipt) {
                                  // @dev Applies the token transfers regarding this send() operation.
                                  // - amountSentLD is the amount in local decimals that was ACTUALLY sent/debited from the sender.
                                  // - amountReceivedLD is the amount in local decimals that will be received/credited to the recipient on the remote OFT instance.
                                  (uint256 amountSentLD, uint256 amountReceivedLD) = _debit(
                                      msg.sender,
                                      _sendParam.amountLD,
                                      _sendParam.minAmountLD,
                                      _sendParam.dstEid
                                  );
                                  // @dev Builds the options and OFT message to quote in the endpoint.
                                  (bytes memory message, bytes memory options) = _buildMsgAndOptions(_sendParam, amountReceivedLD);
                                  // @dev Sends the message to the LayerZero endpoint and returns the LayerZero msg receipt.
                                  msgReceipt = _lzSend(_sendParam.dstEid, message, options, _fee, _refundAddress);
                                  // @dev Formulate the OFT receipt.
                                  oftReceipt = OFTReceipt(amountSentLD, amountReceivedLD);
                                  emit OFTSent(msgReceipt.guid, _sendParam.dstEid, msg.sender, amountSentLD, amountReceivedLD);
                              }
                              /**
                               * @dev Internal function to build the message and options.
                               * @param _sendParam The parameters for the send() operation.
                               * @param _amountLD The amount in local decimals.
                               * @return message The encoded message.
                               * @return options The encoded options.
                               */
                              function _buildMsgAndOptions(
                                  SendParam calldata _sendParam,
                                  uint256 _amountLD
                              ) internal view virtual returns (bytes memory message, bytes memory options) {
                                  bool hasCompose;
                                  // @dev This generated message has the msg.sender encoded into the payload so the remote knows who the caller is.
                                  (message, hasCompose) = OFTMsgCodec.encode(
                                      _sendParam.to,
                                      _toSD(_amountLD),
                                      // @dev Must be include a non empty bytes if you want to compose, EVEN if you dont need it on the remote.
                                      // EVEN if you dont require an arbitrary payload to be sent... eg. '0x01'
                                      _sendParam.composeMsg
                                  );
                                  // @dev Change the msg type depending if its composed or not.
                                  uint16 msgType = hasCompose ? SEND_AND_CALL : SEND;
                                  // @dev Combine the callers _extraOptions with the enforced options via the OAppOptionsType3.
                                  options = combineOptions(_sendParam.dstEid, msgType, _sendParam.extraOptions);
                                  // @dev Optionally inspect the message and options depending if the OApp owner has set a msg inspector.
                                  // @dev If it fails inspection, needs to revert in the implementation. ie. does not rely on return boolean
                                  if (msgInspector != address(0)) IOAppMsgInspector(msgInspector).inspect(message, options);
                              }
                              /**
                               * @dev Internal function to handle the receive on the LayerZero endpoint.
                               * @param _origin The origin information.
                               *  - srcEid: The source chain endpoint ID.
                               *  - sender: The sender address from the src chain.
                               *  - nonce: The nonce of the LayerZero message.
                               * @param _guid The unique identifier for the received LayerZero message.
                               * @param _message The encoded message.
                               * @dev _executor The address of the executor.
                               * @dev _extraData Additional data.
                               */
                              function _lzReceive(
                                  Origin calldata _origin,
                                  bytes32 _guid,
                                  bytes calldata _message,
                                  address /*_executor*/, // @dev unused in the default implementation.
                                  bytes calldata /*_extraData*/ // @dev unused in the default implementation.
                              ) internal virtual override {
                                  // @dev The src sending chain doesnt know the address length on this chain (potentially non-evm)
                                  // Thus everything is bytes32() encoded in flight.
                                  address toAddress = _message.sendTo().bytes32ToAddress();
                                  // @dev Credit the amountLD to the recipient and return the ACTUAL amount the recipient received in local decimals
                                  uint256 amountReceivedLD = _credit(toAddress, _toLD(_message.amountSD()), _origin.srcEid);
                                  if (_message.isComposed()) {
                                      // @dev Proprietary composeMsg format for the OFT.
                                      bytes memory composeMsg = OFTComposeMsgCodec.encode(
                                          _origin.nonce,
                                          _origin.srcEid,
                                          amountReceivedLD,
                                          _message.composeMsg()
                                      );
                                      // @dev Stores the lzCompose payload that will be executed in a separate tx.
                                      // Standardizes functionality for executing arbitrary contract invocation on some non-evm chains.
                                      // @dev The off-chain executor will listen and process the msg based on the src-chain-callers compose options passed.
                                      // @dev The index is used when a OApp needs to compose multiple msgs on lzReceive.
                                      // For default OFT implementation there is only 1 compose msg per lzReceive, thus its always 0.
                                      endpoint.sendCompose(toAddress, _guid, 0 /* the index of the composed message*/, composeMsg);
                                  }
                                  emit OFTReceived(_guid, _origin.srcEid, toAddress, amountReceivedLD);
                              }
                              /**
                               * @dev Internal function to handle the OAppPreCrimeSimulator simulated receive.
                               * @param _origin The origin information.
                               *  - srcEid: The source chain endpoint ID.
                               *  - sender: The sender address from the src chain.
                               *  - nonce: The nonce of the LayerZero message.
                               * @param _guid The unique identifier for the received LayerZero message.
                               * @param _message The LayerZero message.
                               * @param _executor The address of the off-chain executor.
                               * @param _extraData Arbitrary data passed by the msg executor.
                               *
                               * @dev Enables the preCrime simulator to mock sending lzReceive() messages,
                               * routes the msg down from the OAppPreCrimeSimulator, and back up to the OAppReceiver.
                               */
                              function _lzReceiveSimulate(
                                  Origin calldata _origin,
                                  bytes32 _guid,
                                  bytes calldata _message,
                                  address _executor,
                                  bytes calldata _extraData
                              ) internal virtual override {
                                  _lzReceive(_origin, _guid, _message, _executor, _extraData);
                              }
                              /**
                               * @dev Check if the peer is considered 'trusted' by the OApp.
                               * @param _eid The endpoint ID to check.
                               * @param _peer The peer to check.
                               * @return Whether the peer passed is considered 'trusted' by the OApp.
                               *
                               * @dev Enables OAppPreCrimeSimulator to check whether a potential Inbound Packet is from a trusted source.
                               */
                              function isPeer(uint32 _eid, bytes32 _peer) public view virtual override returns (bool) {
                                  return peers[_eid] == _peer;
                              }
                              /**
                               * @dev Internal function to remove dust from the given local decimal amount.
                               * @param _amountLD The amount in local decimals.
                               * @return amountLD The amount after removing dust.
                               *
                               * @dev Prevents the loss of dust when moving amounts between chains with different decimals.
                               * @dev eg. uint(123) with a conversion rate of 100 becomes uint(100).
                               */
                              function _removeDust(uint256 _amountLD) internal view virtual returns (uint256 amountLD) {
                                  return (_amountLD / decimalConversionRate) * decimalConversionRate;
                              }
                              /**
                               * @dev Internal function to convert an amount from shared decimals into local decimals.
                               * @param _amountSD The amount in shared decimals.
                               * @return amountLD The amount in local decimals.
                               */
                              function _toLD(uint64 _amountSD) internal view virtual returns (uint256 amountLD) {
                                  return _amountSD * decimalConversionRate;
                              }
                              /**
                               * @dev Internal function to convert an amount from local decimals into shared decimals.
                               * @param _amountLD The amount in local decimals.
                               * @return amountSD The amount in shared decimals.
                               */
                              function _toSD(uint256 _amountLD) internal view virtual returns (uint64 amountSD) {
                                  return uint64(_amountLD / decimalConversionRate);
                              }
                              /**
                               * @dev Internal function to mock the amount mutation from a OFT debit() operation.
                               * @param _amountLD The amount to send in local decimals.
                               * @param _minAmountLD The minimum amount to send in local decimals.
                               * @dev _dstEid The destination endpoint ID.
                               * @return amountSentLD The amount sent, in local decimals.
                               * @return amountReceivedLD The amount to be received on the remote chain, in local decimals.
                               *
                               * @dev This is where things like fees would be calculated and deducted from the amount to be received on the remote.
                               */
                              function _debitView(
                                  uint256 _amountLD,
                                  uint256 _minAmountLD,
                                  uint32 /*_dstEid*/
                              ) internal view virtual returns (uint256 amountSentLD, uint256 amountReceivedLD) {
                                  // @dev Remove the dust so nothing is lost on the conversion between chains with different decimals for the token.
                                  amountSentLD = _removeDust(_amountLD);
                                  // @dev The amount to send is the same as amount received in the default implementation.
                                  amountReceivedLD = amountSentLD;
                                  // @dev Check for slippage.
                                  if (amountReceivedLD < _minAmountLD) {
                                      revert SlippageExceeded(amountReceivedLD, _minAmountLD);
                                  }
                              }
                              /**
                               * @dev Internal function to perform a debit operation.
                               * @param _from The address to debit.
                               * @param _amountLD The amount to send in local decimals.
                               * @param _minAmountLD The minimum amount to send in local decimals.
                               * @param _dstEid The destination endpoint ID.
                               * @return amountSentLD The amount sent in local decimals.
                               * @return amountReceivedLD The amount received in local decimals on the remote.
                               *
                               * @dev Defined here but are intended to be overriden depending on the OFT implementation.
                               * @dev Depending on OFT implementation the _amountLD could differ from the amountReceivedLD.
                               */
                              function _debit(
                                  address _from,
                                  uint256 _amountLD,
                                  uint256 _minAmountLD,
                                  uint32 _dstEid
                              ) internal virtual returns (uint256 amountSentLD, uint256 amountReceivedLD);
                              /**
                               * @dev Internal function to perform a credit operation.
                               * @param _to The address to credit.
                               * @param _amountLD The amount to credit in local decimals.
                               * @param _srcEid The source endpoint ID.
                               * @return amountReceivedLD The amount ACTUALLY received in local decimals.
                               *
                               * @dev Defined here but are intended to be overriden depending on the OFT implementation.
                               * @dev Depending on OFT implementation the _amountLD could differ from the amountReceivedLD.
                               */
                              function _credit(
                                  address _to,
                                  uint256 _amountLD,
                                  uint32 _srcEid
                              ) internal virtual returns (uint256 amountReceivedLD);
                          }
                          // SPDX-License-Identifier: MIT
                          pragma solidity ^0.8.20;
                          import { MessagingReceipt, MessagingFee } from "../../oapp/OAppSender.sol";
                          /**
                           * @dev Struct representing token parameters for the OFT send() operation.
                           */
                          struct SendParam {
                              uint32 dstEid; // Destination endpoint ID.
                              bytes32 to; // Recipient address.
                              uint256 amountLD; // Amount to send in local decimals.
                              uint256 minAmountLD; // Minimum amount to send in local decimals.
                              bytes extraOptions; // Additional options supplied by the caller to be used in the LayerZero message.
                              bytes composeMsg; // The composed message for the send() operation.
                              bytes oftCmd; // The OFT command to be executed, unused in default OFT implementations.
                          }
                          /**
                           * @dev Struct representing OFT limit information.
                           * @dev These amounts can change dynamically and are up the the specific oft implementation.
                           */
                          struct OFTLimit {
                              uint256 minAmountLD; // Minimum amount in local decimals that can be sent to the recipient.
                              uint256 maxAmountLD; // Maximum amount in local decimals that can be sent to the recipient.
                          }
                          /**
                           * @dev Struct representing OFT receipt information.
                           */
                          struct OFTReceipt {
                              uint256 amountSentLD; // Amount of tokens ACTUALLY debited from the sender in local decimals.
                              // @dev In non-default implementations, the amountReceivedLD COULD differ from this value.
                              uint256 amountReceivedLD; // Amount of tokens to be received on the remote side.
                          }
                          /**
                           * @dev Struct representing OFT fee details.
                           * @dev Future proof mechanism to provide a standardized way to communicate fees to things like a UI.
                           */
                          struct OFTFeeDetail {
                              int256 feeAmountLD; // Amount of the fee in local decimals.
                              string description; // Description of the fee.
                          }
                          /**
                           * @title IOFT
                           * @dev Interface for the OftChain (OFT) token.
                           * @dev Does not inherit ERC20 to accommodate usage by OFTAdapter as well.
                           * @dev This specific interface ID is '0x02e49c2c'.
                           */
                          interface IOFT {
                              // Custom error messages
                              error InvalidLocalDecimals();
                              error SlippageExceeded(uint256 amountLD, uint256 minAmountLD);
                              // Events
                              event OFTSent(
                                  bytes32 indexed guid, // GUID of the OFT message.
                                  uint32 dstEid, // Destination Endpoint ID.
                                  address indexed fromAddress, // Address of the sender on the src chain.
                                  uint256 amountSentLD, // Amount of tokens sent in local decimals.
                                  uint256 amountReceivedLD // Amount of tokens received in local decimals.
                              );
                              event OFTReceived(
                                  bytes32 indexed guid, // GUID of the OFT message.
                                  uint32 srcEid, // Source Endpoint ID.
                                  address indexed toAddress, // Address of the recipient on the dst chain.
                                  uint256 amountReceivedLD // Amount of tokens received in local decimals.
                              );
                              /**
                               * @notice Retrieves interfaceID and the version of the OFT.
                               * @return interfaceId The interface ID.
                               * @return version The version.
                               *
                               * @dev interfaceId: This specific interface ID is '0x02e49c2c'.
                               * @dev version: Indicates a cross-chain compatible msg encoding with other OFTs.
                               * @dev If a new feature is added to the OFT cross-chain msg encoding, the version will be incremented.
                               * ie. localOFT version(x,1) CAN send messages to remoteOFT version(x,1)
                               */
                              function oftVersion() external view returns (bytes4 interfaceId, uint64 version);
                              /**
                               * @notice Retrieves the address of the token associated with the OFT.
                               * @return token The address of the ERC20 token implementation.
                               */
                              function token() external view returns (address);
                              /**
                               * @notice Indicates whether the OFT contract requires approval of the 'token()' to send.
                               * @return requiresApproval Needs approval of the underlying token implementation.
                               *
                               * @dev Allows things like wallet implementers to determine integration requirements,
                               * without understanding the underlying token implementation.
                               */
                              function approvalRequired() external view returns (bool);
                              /**
                               * @notice Retrieves the shared decimals of the OFT.
                               * @return sharedDecimals The shared decimals of the OFT.
                               */
                              function sharedDecimals() external view returns (uint8);
                              /**
                               * @notice Provides a quote for OFT-related operations.
                               * @param _sendParam The parameters for the send operation.
                               * @return limit The OFT limit information.
                               * @return oftFeeDetails The details of OFT fees.
                               * @return receipt The OFT receipt information.
                               */
                              function quoteOFT(
                                  SendParam calldata _sendParam
                              ) external view returns (OFTLimit memory, OFTFeeDetail[] memory oftFeeDetails, OFTReceipt memory);
                              /**
                               * @notice Provides a quote for the send() operation.
                               * @param _sendParam The parameters for the send() operation.
                               * @param _payInLzToken Flag indicating whether the caller is paying in the LZ token.
                               * @return fee The calculated LayerZero messaging fee from the send() operation.
                               *
                               * @dev MessagingFee: LayerZero msg fee
                               *  - nativeFee: The native fee.
                               *  - lzTokenFee: The lzToken fee.
                               */
                              function quoteSend(SendParam calldata _sendParam, bool _payInLzToken) external view returns (MessagingFee memory);
                              /**
                               * @notice Executes the send() operation.
                               * @param _sendParam The parameters for the send operation.
                               * @param _fee The fee information supplied by the caller.
                               *      - nativeFee: The native fee.
                               *      - lzTokenFee: The lzToken fee.
                               * @param _refundAddress The address to receive any excess funds from fees etc. on the src.
                               * @return receipt The LayerZero messaging receipt from the send() operation.
                               * @return oftReceipt The OFT receipt information.
                               *
                               * @dev MessagingReceipt: LayerZero msg receipt
                               *  - guid: The unique identifier for the sent message.
                               *  - nonce: The nonce of the sent message.
                               *  - fee: The LayerZero fee incurred for the message.
                               */
                              function send(
                                  SendParam calldata _sendParam,
                                  MessagingFee calldata _fee,
                                  address _refundAddress
                              ) external payable returns (MessagingReceipt memory, OFTReceipt memory);
                          }
                          // SPDX-License-Identifier: MIT
                          pragma solidity ^0.8.20;
                          library OFTComposeMsgCodec {
                              // Offset constants for decoding composed messages
                              uint8 private constant NONCE_OFFSET = 8;
                              uint8 private constant SRC_EID_OFFSET = 12;
                              uint8 private constant AMOUNT_LD_OFFSET = 44;
                              uint8 private constant COMPOSE_FROM_OFFSET = 76;
                              /**
                               * @dev Encodes a OFT composed message.
                               * @param _nonce The nonce value.
                               * @param _srcEid The source endpoint ID.
                               * @param _amountLD The amount in local decimals.
                               * @param _composeMsg The composed message.
                               * @return _msg The encoded Composed message.
                               */
                              function encode(
                                  uint64 _nonce,
                                  uint32 _srcEid,
                                  uint256 _amountLD,
                                  bytes memory _composeMsg // 0x[composeFrom][composeMsg]
                              ) internal pure returns (bytes memory _msg) {
                                  _msg = abi.encodePacked(_nonce, _srcEid, _amountLD, _composeMsg);
                              }
                              /**
                               * @dev Retrieves the nonce from the composed message.
                               * @param _msg The message.
                               * @return The nonce value.
                               */
                              function nonce(bytes calldata _msg) internal pure returns (uint64) {
                                  return uint64(bytes8(_msg[:NONCE_OFFSET]));
                              }
                              /**
                               * @dev Retrieves the source endpoint ID from the composed message.
                               * @param _msg The message.
                               * @return The source endpoint ID.
                               */
                              function srcEid(bytes calldata _msg) internal pure returns (uint32) {
                                  return uint32(bytes4(_msg[NONCE_OFFSET:SRC_EID_OFFSET]));
                              }
                              /**
                               * @dev Retrieves the amount in local decimals from the composed message.
                               * @param _msg The message.
                               * @return The amount in local decimals.
                               */
                              function amountLD(bytes calldata _msg) internal pure returns (uint256) {
                                  return uint256(bytes32(_msg[SRC_EID_OFFSET:AMOUNT_LD_OFFSET]));
                              }
                              /**
                               * @dev Retrieves the composeFrom value from the composed message.
                               * @param _msg The message.
                               * @return The composeFrom value.
                               */
                              function composeFrom(bytes calldata _msg) internal pure returns (bytes32) {
                                  return bytes32(_msg[AMOUNT_LD_OFFSET:COMPOSE_FROM_OFFSET]);
                              }
                              /**
                               * @dev Retrieves the composed message.
                               * @param _msg The message.
                               * @return The composed message.
                               */
                              function composeMsg(bytes calldata _msg) internal pure returns (bytes memory) {
                                  return _msg[COMPOSE_FROM_OFFSET:];
                              }
                              /**
                               * @dev Converts an address to bytes32.
                               * @param _addr The address to convert.
                               * @return The bytes32 representation of the address.
                               */
                              function addressToBytes32(address _addr) internal pure returns (bytes32) {
                                  return bytes32(uint256(uint160(_addr)));
                              }
                              /**
                               * @dev Converts bytes32 to an address.
                               * @param _b The bytes32 value to convert.
                               * @return The address representation of bytes32.
                               */
                              function bytes32ToAddress(bytes32 _b) internal pure returns (address) {
                                  return address(uint160(uint256(_b)));
                              }
                          }
                          // SPDX-License-Identifier: MIT
                          pragma solidity ^0.8.20;
                          library OFTMsgCodec {
                              // Offset constants for encoding and decoding OFT messages
                              uint8 private constant SEND_TO_OFFSET = 32;
                              uint8 private constant SEND_AMOUNT_SD_OFFSET = 40;
                              /**
                               * @dev Encodes an OFT LayerZero message.
                               * @param _sendTo The recipient address.
                               * @param _amountShared The amount in shared decimals.
                               * @param _composeMsg The composed message.
                               * @return _msg The encoded message.
                               * @return hasCompose A boolean indicating whether the message has a composed payload.
                               */
                              function encode(
                                  bytes32 _sendTo,
                                  uint64 _amountShared,
                                  bytes memory _composeMsg
                              ) internal view returns (bytes memory _msg, bool hasCompose) {
                                  hasCompose = _composeMsg.length > 0;
                                  // @dev Remote chains will want to know the composed function caller ie. msg.sender on the src.
                                  _msg = hasCompose
                                      ? abi.encodePacked(_sendTo, _amountShared, addressToBytes32(msg.sender), _composeMsg)
                                      : abi.encodePacked(_sendTo, _amountShared);
                              }
                              /**
                               * @dev Checks if the OFT message is composed.
                               * @param _msg The OFT message.
                               * @return A boolean indicating whether the message is composed.
                               */
                              function isComposed(bytes calldata _msg) internal pure returns (bool) {
                                  return _msg.length > SEND_AMOUNT_SD_OFFSET;
                              }
                              /**
                               * @dev Retrieves the recipient address from the OFT message.
                               * @param _msg The OFT message.
                               * @return The recipient address.
                               */
                              function sendTo(bytes calldata _msg) internal pure returns (bytes32) {
                                  return bytes32(_msg[:SEND_TO_OFFSET]);
                              }
                              /**
                               * @dev Retrieves the amount in shared decimals from the OFT message.
                               * @param _msg The OFT message.
                               * @return The amount in shared decimals.
                               */
                              function amountSD(bytes calldata _msg) internal pure returns (uint64) {
                                  return uint64(bytes8(_msg[SEND_TO_OFFSET:SEND_AMOUNT_SD_OFFSET]));
                              }
                              /**
                               * @dev Retrieves the composed message from the OFT message.
                               * @param _msg The OFT message.
                               * @return The composed message.
                               */
                              function composeMsg(bytes calldata _msg) internal pure returns (bytes memory) {
                                  return _msg[SEND_AMOUNT_SD_OFFSET:];
                              }
                              /**
                               * @dev Converts an address to bytes32.
                               * @param _addr The address to convert.
                               * @return The bytes32 representation of the address.
                               */
                              function addressToBytes32(address _addr) internal pure returns (bytes32) {
                                  return bytes32(uint256(uint160(_addr)));
                              }
                              /**
                               * @dev Converts bytes32 to an address.
                               * @param _b The bytes32 value to convert.
                               * @return The address representation of bytes32.
                               */
                              function bytes32ToAddress(bytes32 _b) internal pure returns (address) {
                                  return address(uint160(uint256(_b)));
                              }
                          }
                          // SPDX-License-Identifier: MIT
                          pragma solidity ^0.8.20;
                          import { Ownable } from "@openzeppelin/contracts/access/Ownable.sol";
                          import { IPreCrime } from "./interfaces/IPreCrime.sol";
                          import { IOAppPreCrimeSimulator, InboundPacket, Origin } from "./interfaces/IOAppPreCrimeSimulator.sol";
                          /**
                           * @title OAppPreCrimeSimulator
                           * @dev Abstract contract serving as the base for preCrime simulation functionality in an OApp.
                           */
                          abstract contract OAppPreCrimeSimulator is IOAppPreCrimeSimulator, Ownable {
                              // The address of the preCrime implementation.
                              address public preCrime;
                              /**
                               * @dev Retrieves the address of the OApp contract.
                               * @return The address of the OApp contract.
                               *
                               * @dev The simulator contract is the base contract for the OApp by default.
                               * @dev If the simulator is a separate contract, override this function.
                               */
                              function oApp() external view virtual returns (address) {
                                  return address(this);
                              }
                              /**
                               * @dev Sets the preCrime contract address.
                               * @param _preCrime The address of the preCrime contract.
                               */
                              function setPreCrime(address _preCrime) public virtual onlyOwner {
                                  preCrime = _preCrime;
                                  emit PreCrimeSet(_preCrime);
                              }
                              /**
                               * @dev Interface for pre-crime simulations. Always reverts at the end with the simulation results.
                               * @param _packets An array of InboundPacket objects representing received packets to be delivered.
                               *
                               * @dev WARNING: MUST revert at the end with the simulation results.
                               * @dev Gives the preCrime implementation the ability to mock sending packets to the lzReceive function,
                               * WITHOUT actually executing them.
                               */
                              function lzReceiveAndRevert(InboundPacket[] calldata _packets) public payable virtual {
                                  for (uint256 i = 0; i < _packets.length; i++) {
                                      InboundPacket calldata packet = _packets[i];
                                      // Ignore packets that are not from trusted peers.
                                      if (!isPeer(packet.origin.srcEid, packet.origin.sender)) continue;
                                      // @dev Because a verifier is calling this function, it doesnt have access to executor params:
                                      //  - address _executor
                                      //  - bytes calldata _extraData
                                      // preCrime will NOT work for OApps that rely on these two parameters inside of their _lzReceive().
                                      // They are instead stubbed to default values, address(0) and bytes("")
                                      // @dev Calling this.lzReceiveSimulate removes ability for assembly return 0 callstack exit,
                                      // which would cause the revert to be ignored.
                                      this.lzReceiveSimulate{ value: packet.value }(
                                          packet.origin,
                                          packet.guid,
                                          packet.message,
                                          packet.executor,
                                          packet.extraData
                                      );
                                  }
                                  // @dev Revert with the simulation results. msg.sender must implement IPreCrime.buildSimulationResult().
                                  revert SimulationResult(IPreCrime(msg.sender).buildSimulationResult());
                              }
                              /**
                               * @dev Is effectively an internal function because msg.sender must be address(this).
                               * Allows resetting the call stack for 'internal' calls.
                               * @param _origin The origin information containing the source endpoint and sender address.
                               *  - srcEid: The source chain endpoint ID.
                               *  - sender: The sender address on the src chain.
                               *  - nonce: The nonce of the message.
                               * @param _guid The unique identifier of the packet.
                               * @param _message The message payload of the packet.
                               * @param _executor The executor address for the packet.
                               * @param _extraData Additional data for the packet.
                               */
                              function lzReceiveSimulate(
                                  Origin calldata _origin,
                                  bytes32 _guid,
                                  bytes calldata _message,
                                  address _executor,
                                  bytes calldata _extraData
                              ) external payable virtual {
                                  // @dev Ensure ONLY can be called 'internally'.
                                  if (msg.sender != address(this)) revert OnlySelf();
                                  _lzReceiveSimulate(_origin, _guid, _message, _executor, _extraData);
                              }
                              /**
                               * @dev Internal function to handle the OAppPreCrimeSimulator simulated receive.
                               * @param _origin The origin information.
                               *  - srcEid: The source chain endpoint ID.
                               *  - sender: The sender address from the src chain.
                               *  - nonce: The nonce of the LayerZero message.
                               * @param _guid The GUID of the LayerZero message.
                               * @param _message The LayerZero message.
                               * @param _executor The address of the off-chain executor.
                               * @param _extraData Arbitrary data passed by the msg executor.
                               *
                               * @dev Enables the preCrime simulator to mock sending lzReceive() messages,
                               * routes the msg down from the OAppPreCrimeSimulator, and back up to the OAppReceiver.
                               */
                              function _lzReceiveSimulate(
                                  Origin calldata _origin,
                                  bytes32 _guid,
                                  bytes calldata _message,
                                  address _executor,
                                  bytes calldata _extraData
                              ) internal virtual;
                              /**
                               * @dev checks if the specified peer is considered 'trusted' by the OApp.
                               * @param _eid The endpoint Id to check.
                               * @param _peer The peer to check.
                               * @return Whether the peer passed is considered 'trusted' by the OApp.
                               */
                              function isPeer(uint32 _eid, bytes32 _peer) public view virtual returns (bool);
                          }
                          // SPDX-License-Identifier: MIT
                          pragma solidity ^0.8.20;
                          // @dev Import the Origin so it's exposed to OAppPreCrimeSimulator implementers.
                          // solhint-disable-next-line no-unused-import
                          import { InboundPacket, Origin } from "../libs/Packet.sol";
                          /**
                           * @title IOAppPreCrimeSimulator Interface
                           * @dev Interface for the preCrime simulation functionality in an OApp.
                           */
                          interface IOAppPreCrimeSimulator {
                              // @dev simulation result used in PreCrime implementation
                              error SimulationResult(bytes result);
                              error OnlySelf();
                              /**
                               * @dev Emitted when the preCrime contract address is set.
                               * @param preCrimeAddress The address of the preCrime contract.
                               */
                              event PreCrimeSet(address preCrimeAddress);
                              /**
                               * @dev Retrieves the address of the preCrime contract implementation.
                               * @return The address of the preCrime contract.
                               */
                              function preCrime() external view returns (address);
                              /**
                               * @dev Retrieves the address of the OApp contract.
                               * @return The address of the OApp contract.
                               */
                              function oApp() external view returns (address);
                              /**
                               * @dev Sets the preCrime contract address.
                               * @param _preCrime The address of the preCrime contract.
                               */
                              function setPreCrime(address _preCrime) external;
                              /**
                               * @dev Mocks receiving a packet, then reverts with a series of data to infer the state/result.
                               * @param _packets An array of LayerZero InboundPacket objects representing received packets.
                               */
                              function lzReceiveAndRevert(InboundPacket[] calldata _packets) external payable;
                              /**
                               * @dev checks if the specified peer is considered 'trusted' by the OApp.
                               * @param _eid The endpoint Id to check.
                               * @param _peer The peer to check.
                               * @return Whether the peer passed is considered 'trusted' by the OApp.
                               */
                              function isPeer(uint32 _eid, bytes32 _peer) external view returns (bool);
                          }
                          // SPDX-License-Identifier: MIT
                          pragma solidity ^0.8.20;
                          struct PreCrimePeer {
                              uint32 eid;
                              bytes32 preCrime;
                              bytes32 oApp;
                          }
                          // TODO not done yet
                          interface IPreCrime {
                              error OnlyOffChain();
                              // for simulate()
                              error PacketOversize(uint256 max, uint256 actual);
                              error PacketUnsorted();
                              error SimulationFailed(bytes reason);
                              // for preCrime()
                              error SimulationResultNotFound(uint32 eid);
                              error InvalidSimulationResult(uint32 eid, bytes reason);
                              error CrimeFound(bytes crime);
                              function getConfig(bytes[] calldata _packets, uint256[] calldata _packetMsgValues) external returns (bytes memory);
                              function simulate(
                                  bytes[] calldata _packets,
                                  uint256[] calldata _packetMsgValues
                              ) external payable returns (bytes memory);
                              function buildSimulationResult() external view returns (bytes memory);
                              function preCrime(
                                  bytes[] calldata _packets,
                                  uint256[] calldata _packetMsgValues,
                                  bytes[] calldata _simulations
                              ) external;
                              function version() external view returns (uint64 major, uint8 minor);
                          }
                          // SPDX-License-Identifier: MIT
                          pragma solidity ^0.8.20;
                          import { Origin } from "@layerzerolabs/lz-evm-protocol-v2/contracts/interfaces/ILayerZeroEndpointV2.sol";
                          import { PacketV1Codec } from "@layerzerolabs/lz-evm-protocol-v2/contracts/messagelib/libs/PacketV1Codec.sol";
                          /**
                           * @title InboundPacket
                           * @dev Structure representing an inbound packet received by the contract.
                           */
                          struct InboundPacket {
                              Origin origin; // Origin information of the packet.
                              uint32 dstEid; // Destination endpointId of the packet.
                              address receiver; // Receiver address for the packet.
                              bytes32 guid; // Unique identifier of the packet.
                              uint256 value; // msg.value of the packet.
                              address executor; // Executor address for the packet.
                              bytes message; // Message payload of the packet.
                              bytes extraData; // Additional arbitrary data for the packet.
                          }
                          /**
                           * @title PacketDecoder
                           * @dev Library for decoding LayerZero packets.
                           */
                          library PacketDecoder {
                              using PacketV1Codec for bytes;
                              /**
                               * @dev Decode an inbound packet from the given packet data.
                               * @param _packet The packet data to decode.
                               * @return packet An InboundPacket struct representing the decoded packet.
                               */
                              function decode(bytes calldata _packet) internal pure returns (InboundPacket memory packet) {
                                  packet.origin = Origin(_packet.srcEid(), _packet.sender(), _packet.nonce());
                                  packet.dstEid = _packet.dstEid();
                                  packet.receiver = _packet.receiverB20();
                                  packet.guid = _packet.guid();
                                  packet.message = _packet.message();
                              }
                              /**
                               * @dev Decode multiple inbound packets from the given packet data and associated message values.
                               * @param _packets An array of packet data to decode.
                               * @param _packetMsgValues An array of associated message values for each packet.
                               * @return packets An array of InboundPacket structs representing the decoded packets.
                               */
                              function decode(
                                  bytes[] calldata _packets,
                                  uint256[] memory _packetMsgValues
                              ) internal pure returns (InboundPacket[] memory packets) {
                                  packets = new InboundPacket[](_packets.length);
                                  for (uint256 i = 0; i < _packets.length; i++) {
                                      bytes calldata packet = _packets[i];
                                      packets[i] = PacketDecoder.decode(packet);
                                      // @dev Allows the verifier to specify the msg.value that gets passed in lzReceive.
                                      packets[i].value = _packetMsgValues[i];
                                  }
                              }
                          }
                          // SPDX-License-Identifier: MIT
                          pragma solidity >=0.8.0;
                          import { IMessageLibManager } from "./IMessageLibManager.sol";
                          import { IMessagingComposer } from "./IMessagingComposer.sol";
                          import { IMessagingChannel } from "./IMessagingChannel.sol";
                          import { IMessagingContext } from "./IMessagingContext.sol";
                          struct MessagingParams {
                              uint32 dstEid;
                              bytes32 receiver;
                              bytes message;
                              bytes options;
                              bool payInLzToken;
                          }
                          struct MessagingReceipt {
                              bytes32 guid;
                              uint64 nonce;
                              MessagingFee fee;
                          }
                          struct MessagingFee {
                              uint256 nativeFee;
                              uint256 lzTokenFee;
                          }
                          struct Origin {
                              uint32 srcEid;
                              bytes32 sender;
                              uint64 nonce;
                          }
                          interface ILayerZeroEndpointV2 is IMessageLibManager, IMessagingComposer, IMessagingChannel, IMessagingContext {
                              event PacketSent(bytes encodedPayload, bytes options, address sendLibrary);
                              event PacketVerified(Origin origin, address receiver, bytes32 payloadHash);
                              event PacketDelivered(Origin origin, address receiver);
                              event LzReceiveAlert(
                                  address indexed receiver,
                                  address indexed executor,
                                  Origin origin,
                                  bytes32 guid,
                                  uint256 gas,
                                  uint256 value,
                                  bytes message,
                                  bytes extraData,
                                  bytes reason
                              );
                              event LzTokenSet(address token);
                              event DelegateSet(address sender, address delegate);
                              function quote(MessagingParams calldata _params, address _sender) external view returns (MessagingFee memory);
                              function send(
                                  MessagingParams calldata _params,
                                  address _refundAddress
                              ) external payable returns (MessagingReceipt memory);
                              function verify(Origin calldata _origin, address _receiver, bytes32 _payloadHash) external;
                              function verifiable(Origin calldata _origin, address _receiver) external view returns (bool);
                              function initializable(Origin calldata _origin, address _receiver) external view returns (bool);
                              function lzReceive(
                                  Origin calldata _origin,
                                  address _receiver,
                                  bytes32 _guid,
                                  bytes calldata _message,
                                  bytes calldata _extraData
                              ) external payable;
                              // oapp can burn messages partially by calling this function with its own business logic if messages are verified in order
                              function clear(address _oapp, Origin calldata _origin, bytes32 _guid, bytes calldata _message) external;
                              function setLzToken(address _lzToken) external;
                              function lzToken() external view returns (address);
                              function nativeToken() external view returns (address);
                              function setDelegate(address _delegate) external;
                          }
                          // SPDX-License-Identifier: MIT
                          pragma solidity >=0.8.0;
                          import { Origin } from "./ILayerZeroEndpointV2.sol";
                          interface ILayerZeroReceiver {
                              function allowInitializePath(Origin calldata _origin) external view returns (bool);
                              function nextNonce(uint32 _eid, bytes32 _sender) external view returns (uint64);
                              function lzReceive(
                                  Origin calldata _origin,
                                  bytes32 _guid,
                                  bytes calldata _message,
                                  address _executor,
                                  bytes calldata _extraData
                              ) external payable;
                          }
                          // SPDX-License-Identifier: MIT
                          pragma solidity >=0.8.0;
                          import { IERC165 } from "@openzeppelin/contracts/utils/introspection/IERC165.sol";
                          import { SetConfigParam } from "./IMessageLibManager.sol";
                          enum MessageLibType {
                              Send,
                              Receive,
                              SendAndReceive
                          }
                          interface IMessageLib is IERC165 {
                              function setConfig(address _oapp, SetConfigParam[] calldata _config) external;
                              function getConfig(uint32 _eid, address _oapp, uint32 _configType) external view returns (bytes memory config);
                              function isSupportedEid(uint32 _eid) external view returns (bool);
                              // message libs of same major version are compatible
                              function version() external view returns (uint64 major, uint8 minor, uint8 endpointVersion);
                              function messageLibType() external view returns (MessageLibType);
                          }
                          // SPDX-License-Identifier: MIT
                          pragma solidity >=0.8.0;
                          struct SetConfigParam {
                              uint32 eid;
                              uint32 configType;
                              bytes config;
                          }
                          interface IMessageLibManager {
                              struct Timeout {
                                  address lib;
                                  uint256 expiry;
                              }
                              event LibraryRegistered(address newLib);
                              event DefaultSendLibrarySet(uint32 eid, address newLib);
                              event DefaultReceiveLibrarySet(uint32 eid, address newLib);
                              event DefaultReceiveLibraryTimeoutSet(uint32 eid, address oldLib, uint256 expiry);
                              event SendLibrarySet(address sender, uint32 eid, address newLib);
                              event ReceiveLibrarySet(address receiver, uint32 eid, address newLib);
                              event ReceiveLibraryTimeoutSet(address receiver, uint32 eid, address oldLib, uint256 timeout);
                              function registerLibrary(address _lib) external;
                              function isRegisteredLibrary(address _lib) external view returns (bool);
                              function getRegisteredLibraries() external view returns (address[] memory);
                              function setDefaultSendLibrary(uint32 _eid, address _newLib) external;
                              function defaultSendLibrary(uint32 _eid) external view returns (address);
                              function setDefaultReceiveLibrary(uint32 _eid, address _newLib, uint256 _timeout) external;
                              function defaultReceiveLibrary(uint32 _eid) external view returns (address);
                              function setDefaultReceiveLibraryTimeout(uint32 _eid, address _lib, uint256 _expiry) external;
                              function defaultReceiveLibraryTimeout(uint32 _eid) external view returns (address lib, uint256 expiry);
                              function isSupportedEid(uint32 _eid) external view returns (bool);
                              function isValidReceiveLibrary(address _receiver, uint32 _eid, address _lib) external view returns (bool);
                              /// ------------------- OApp interfaces -------------------
                              function setSendLibrary(address _oapp, uint32 _eid, address _newLib) external;
                              function getSendLibrary(address _sender, uint32 _eid) external view returns (address lib);
                              function isDefaultSendLibrary(address _sender, uint32 _eid) external view returns (bool);
                              function setReceiveLibrary(address _oapp, uint32 _eid, address _newLib, uint256 _gracePeriod) external;
                              function getReceiveLibrary(address _receiver, uint32 _eid) external view returns (address lib, bool isDefault);
                              function setReceiveLibraryTimeout(address _oapp, uint32 _eid, address _lib, uint256 _gracePeriod) external;
                              function receiveLibraryTimeout(address _receiver, uint32 _eid) external view returns (address lib, uint256 expiry);
                              function setConfig(address _oapp, address _lib, SetConfigParam[] calldata _params) external;
                              function getConfig(
                                  address _oapp,
                                  address _lib,
                                  uint32 _eid,
                                  uint32 _configType
                              ) external view returns (bytes memory config);
                          }
                          // SPDX-License-Identifier: MIT
                          pragma solidity >=0.8.0;
                          interface IMessagingChannel {
                              event InboundNonceSkipped(uint32 srcEid, bytes32 sender, address receiver, uint64 nonce);
                              event PacketNilified(uint32 srcEid, bytes32 sender, address receiver, uint64 nonce, bytes32 payloadHash);
                              event PacketBurnt(uint32 srcEid, bytes32 sender, address receiver, uint64 nonce, bytes32 payloadHash);
                              function eid() external view returns (uint32);
                              // this is an emergency function if a message cannot be verified for some reasons
                              // required to provide _nextNonce to avoid race condition
                              function skip(address _oapp, uint32 _srcEid, bytes32 _sender, uint64 _nonce) external;
                              function nilify(address _oapp, uint32 _srcEid, bytes32 _sender, uint64 _nonce, bytes32 _payloadHash) external;
                              function burn(address _oapp, uint32 _srcEid, bytes32 _sender, uint64 _nonce, bytes32 _payloadHash) external;
                              function nextGuid(address _sender, uint32 _dstEid, bytes32 _receiver) external view returns (bytes32);
                              function inboundNonce(address _receiver, uint32 _srcEid, bytes32 _sender) external view returns (uint64);
                              function outboundNonce(address _sender, uint32 _dstEid, bytes32 _receiver) external view returns (uint64);
                              function inboundPayloadHash(
                                  address _receiver,
                                  uint32 _srcEid,
                                  bytes32 _sender,
                                  uint64 _nonce
                              ) external view returns (bytes32);
                              function lazyInboundNonce(address _receiver, uint32 _srcEid, bytes32 _sender) external view returns (uint64);
                          }
                          // SPDX-License-Identifier: MIT
                          pragma solidity >=0.8.0;
                          interface IMessagingComposer {
                              event ComposeSent(address from, address to, bytes32 guid, uint16 index, bytes message);
                              event ComposeDelivered(address from, address to, bytes32 guid, uint16 index);
                              event LzComposeAlert(
                                  address indexed from,
                                  address indexed to,
                                  address indexed executor,
                                  bytes32 guid,
                                  uint16 index,
                                  uint256 gas,
                                  uint256 value,
                                  bytes message,
                                  bytes extraData,
                                  bytes reason
                              );
                              function composeQueue(
                                  address _from,
                                  address _to,
                                  bytes32 _guid,
                                  uint16 _index
                              ) external view returns (bytes32 messageHash);
                              function sendCompose(address _to, bytes32 _guid, uint16 _index, bytes calldata _message) external;
                              function lzCompose(
                                  address _from,
                                  address _to,
                                  bytes32 _guid,
                                  uint16 _index,
                                  bytes calldata _message,
                                  bytes calldata _extraData
                              ) external payable;
                          }
                          // SPDX-License-Identifier: MIT
                          pragma solidity >=0.8.0;
                          interface IMessagingContext {
                              function isSendingMessage() external view returns (bool);
                              function getSendContext() external view returns (uint32 dstEid, address sender);
                          }
                          // SPDX-License-Identifier: MIT
                          pragma solidity >=0.8.0;
                          import { MessagingFee } from "./ILayerZeroEndpointV2.sol";
                          import { IMessageLib } from "./IMessageLib.sol";
                          struct Packet {
                              uint64 nonce;
                              uint32 srcEid;
                              address sender;
                              uint32 dstEid;
                              bytes32 receiver;
                              bytes32 guid;
                              bytes message;
                          }
                          interface ISendLib is IMessageLib {
                              function send(
                                  Packet calldata _packet,
                                  bytes calldata _options,
                                  bool _payInLzToken
                              ) external returns (MessagingFee memory, bytes memory encodedPacket);
                              function quote(
                                  Packet calldata _packet,
                                  bytes calldata _options,
                                  bool _payInLzToken
                              ) external view returns (MessagingFee memory);
                              function setTreasury(address _treasury) external;
                              function withdrawFee(address _to, uint256 _amount) external;
                              function withdrawLzTokenFee(address _lzToken, address _to, uint256 _amount) external;
                          }
                          // SPDX-License-Identifier: LZBL-1.2
                          pragma solidity ^0.8.20;
                          library AddressCast {
                              error AddressCast_InvalidSizeForAddress();
                              error AddressCast_InvalidAddress();
                              function toBytes32(bytes calldata _addressBytes) internal pure returns (bytes32 result) {
                                  if (_addressBytes.length > 32) revert AddressCast_InvalidAddress();
                                  result = bytes32(_addressBytes);
                                  unchecked {
                                      uint256 offset = 32 - _addressBytes.length;
                                      result = result >> (offset * 8);
                                  }
                              }
                              function toBytes32(address _address) internal pure returns (bytes32 result) {
                                  result = bytes32(uint256(uint160(_address)));
                              }
                              function toBytes(bytes32 _addressBytes32, uint256 _size) internal pure returns (bytes memory result) {
                                  if (_size == 0 || _size > 32) revert AddressCast_InvalidSizeForAddress();
                                  result = new bytes(_size);
                                  unchecked {
                                      uint256 offset = 256 - _size * 8;
                                      assembly {
                                          mstore(add(result, 32), shl(offset, _addressBytes32))
                                      }
                                  }
                              }
                              function toAddress(bytes32 _addressBytes32) internal pure returns (address result) {
                                  result = address(uint160(uint256(_addressBytes32)));
                              }
                              function toAddress(bytes calldata _addressBytes) internal pure returns (address result) {
                                  if (_addressBytes.length != 20) revert AddressCast_InvalidAddress();
                                  result = address(bytes20(_addressBytes));
                              }
                          }
                          // SPDX-License-Identifier: LZBL-1.2
                          pragma solidity ^0.8.20;
                          import { Packet } from "../../interfaces/ISendLib.sol";
                          import { AddressCast } from "../../libs/AddressCast.sol";
                          library PacketV1Codec {
                              using AddressCast for address;
                              using AddressCast for bytes32;
                              uint8 internal constant PACKET_VERSION = 1;
                              // header (version + nonce + path)
                              // version
                              uint256 private constant PACKET_VERSION_OFFSET = 0;
                              //    nonce
                              uint256 private constant NONCE_OFFSET = 1;
                              //    path
                              uint256 private constant SRC_EID_OFFSET = 9;
                              uint256 private constant SENDER_OFFSET = 13;
                              uint256 private constant DST_EID_OFFSET = 45;
                              uint256 private constant RECEIVER_OFFSET = 49;
                              // payload (guid + message)
                              uint256 private constant GUID_OFFSET = 81; // keccak256(nonce + path)
                              uint256 private constant MESSAGE_OFFSET = 113;
                              function encode(Packet memory _packet) internal pure returns (bytes memory encodedPacket) {
                                  encodedPacket = abi.encodePacked(
                                      PACKET_VERSION,
                                      _packet.nonce,
                                      _packet.srcEid,
                                      _packet.sender.toBytes32(),
                                      _packet.dstEid,
                                      _packet.receiver,
                                      _packet.guid,
                                      _packet.message
                                  );
                              }
                              function encodePacketHeader(Packet memory _packet) internal pure returns (bytes memory) {
                                  return
                                      abi.encodePacked(
                                          PACKET_VERSION,
                                          _packet.nonce,
                                          _packet.srcEid,
                                          _packet.sender.toBytes32(),
                                          _packet.dstEid,
                                          _packet.receiver
                                      );
                              }
                              function encodePayload(Packet memory _packet) internal pure returns (bytes memory) {
                                  return abi.encodePacked(_packet.guid, _packet.message);
                              }
                              function header(bytes calldata _packet) internal pure returns (bytes calldata) {
                                  return _packet[0:GUID_OFFSET];
                              }
                              function version(bytes calldata _packet) internal pure returns (uint8) {
                                  return uint8(bytes1(_packet[PACKET_VERSION_OFFSET:NONCE_OFFSET]));
                              }
                              function nonce(bytes calldata _packet) internal pure returns (uint64) {
                                  return uint64(bytes8(_packet[NONCE_OFFSET:SRC_EID_OFFSET]));
                              }
                              function srcEid(bytes calldata _packet) internal pure returns (uint32) {
                                  return uint32(bytes4(_packet[SRC_EID_OFFSET:SENDER_OFFSET]));
                              }
                              function sender(bytes calldata _packet) internal pure returns (bytes32) {
                                  return bytes32(_packet[SENDER_OFFSET:DST_EID_OFFSET]);
                              }
                              function senderAddressB20(bytes calldata _packet) internal pure returns (address) {
                                  return sender(_packet).toAddress();
                              }
                              function dstEid(bytes calldata _packet) internal pure returns (uint32) {
                                  return uint32(bytes4(_packet[DST_EID_OFFSET:RECEIVER_OFFSET]));
                              }
                              function receiver(bytes calldata _packet) internal pure returns (bytes32) {
                                  return bytes32(_packet[RECEIVER_OFFSET:GUID_OFFSET]);
                              }
                              function receiverB20(bytes calldata _packet) internal pure returns (address) {
                                  return receiver(_packet).toAddress();
                              }
                              function guid(bytes calldata _packet) internal pure returns (bytes32) {
                                  return bytes32(_packet[GUID_OFFSET:MESSAGE_OFFSET]);
                              }
                              function message(bytes calldata _packet) internal pure returns (bytes calldata) {
                                  return bytes(_packet[MESSAGE_OFFSET:]);
                              }
                              function payload(bytes calldata _packet) internal pure returns (bytes calldata) {
                                  return bytes(_packet[GUID_OFFSET:]);
                              }
                              function payloadHash(bytes calldata _packet) internal pure returns (bytes32) {
                                  return keccak256(payload(_packet));
                              }
                          }
                          // SPDX-License-Identifier: MIT
                          // OpenZeppelin Contracts (last updated v5.0.0) (access/Ownable.sol)
                          pragma solidity ^0.8.20;
                          import {Context} from "../utils/Context.sol";
                          /**
                           * @dev Contract module which provides a basic access control mechanism, where
                           * there is an account (an owner) that can be granted exclusive access to
                           * specific functions.
                           *
                           * The initial owner is set to the address provided by the deployer. This can
                           * later be changed with {transferOwnership}.
                           *
                           * This module is used through inheritance. It will make available the modifier
                           * `onlyOwner`, which can be applied to your functions to restrict their use to
                           * the owner.
                           */
                          abstract contract Ownable is Context {
                              address private _owner;
                              /**
                               * @dev The caller account is not authorized to perform an operation.
                               */
                              error OwnableUnauthorizedAccount(address account);
                              /**
                               * @dev The owner is not a valid owner account. (eg. `address(0)`)
                               */
                              error OwnableInvalidOwner(address owner);
                              event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);
                              /**
                               * @dev Initializes the contract setting the address provided by the deployer as the initial owner.
                               */
                              constructor(address initialOwner) {
                                  if (initialOwner == address(0)) {
                                      revert OwnableInvalidOwner(address(0));
                                  }
                                  _transferOwnership(initialOwner);
                              }
                              /**
                               * @dev Throws if called by any account other than the owner.
                               */
                              modifier onlyOwner() {
                                  _checkOwner();
                                  _;
                              }
                              /**
                               * @dev Returns the address of the current owner.
                               */
                              function owner() public view virtual returns (address) {
                                  return _owner;
                              }
                              /**
                               * @dev Throws if the sender is not the owner.
                               */
                              function _checkOwner() internal view virtual {
                                  if (owner() != _msgSender()) {
                                      revert OwnableUnauthorizedAccount(_msgSender());
                                  }
                              }
                              /**
                               * @dev Leaves the contract without owner. It will not be possible to call
                               * `onlyOwner` functions. Can only be called by the current owner.
                               *
                               * NOTE: Renouncing ownership will leave the contract without an owner,
                               * thereby disabling any functionality that is only available to the owner.
                               */
                              function renounceOwnership() public virtual onlyOwner {
                                  _transferOwnership(address(0));
                              }
                              /**
                               * @dev Transfers ownership of the contract to a new account (`newOwner`).
                               * Can only be called by the current owner.
                               */
                              function transferOwnership(address newOwner) public virtual onlyOwner {
                                  if (newOwner == address(0)) {
                                      revert OwnableInvalidOwner(address(0));
                                  }
                                  _transferOwnership(newOwner);
                              }
                              /**
                               * @dev Transfers ownership of the contract to a new account (`newOwner`).
                               * Internal function without access restriction.
                               */
                              function _transferOwnership(address newOwner) internal virtual {
                                  address oldOwner = _owner;
                                  _owner = newOwner;
                                  emit OwnershipTransferred(oldOwner, newOwner);
                              }
                          }
                          // SPDX-License-Identifier: MIT
                          // OpenZeppelin Contracts (last updated v5.0.0) (interfaces/draft-IERC6093.sol)
                          pragma solidity ^0.8.20;
                          /**
                           * @dev Standard ERC20 Errors
                           * Interface of the https://eips.ethereum.org/EIPS/eip-6093[ERC-6093] custom errors for ERC20 tokens.
                           */
                          interface IERC20Errors {
                              /**
                               * @dev Indicates an error related to the current `balance` of a `sender`. Used in transfers.
                               * @param sender Address whose tokens are being transferred.
                               * @param balance Current balance for the interacting account.
                               * @param needed Minimum amount required to perform a transfer.
                               */
                              error ERC20InsufficientBalance(address sender, uint256 balance, uint256 needed);
                              /**
                               * @dev Indicates a failure with the token `sender`. Used in transfers.
                               * @param sender Address whose tokens are being transferred.
                               */
                              error ERC20InvalidSender(address sender);
                              /**
                               * @dev Indicates a failure with the token `receiver`. Used in transfers.
                               * @param receiver Address to which tokens are being transferred.
                               */
                              error ERC20InvalidReceiver(address receiver);
                              /**
                               * @dev Indicates a failure with the `spender`’s `allowance`. Used in transfers.
                               * @param spender Address that may be allowed to operate on tokens without being their owner.
                               * @param allowance Amount of tokens a `spender` is allowed to operate with.
                               * @param needed Minimum amount required to perform a transfer.
                               */
                              error ERC20InsufficientAllowance(address spender, uint256 allowance, uint256 needed);
                              /**
                               * @dev Indicates a failure with the `approver` of a token to be approved. Used in approvals.
                               * @param approver Address initiating an approval operation.
                               */
                              error ERC20InvalidApprover(address approver);
                              /**
                               * @dev Indicates a failure with the `spender` to be approved. Used in approvals.
                               * @param spender Address that may be allowed to operate on tokens without being their owner.
                               */
                              error ERC20InvalidSpender(address spender);
                          }
                          /**
                           * @dev Standard ERC721 Errors
                           * Interface of the https://eips.ethereum.org/EIPS/eip-6093[ERC-6093] custom errors for ERC721 tokens.
                           */
                          interface IERC721Errors {
                              /**
                               * @dev Indicates that an address can't be an owner. For example, `address(0)` is a forbidden owner in EIP-20.
                               * Used in balance queries.
                               * @param owner Address of the current owner of a token.
                               */
                              error ERC721InvalidOwner(address owner);
                              /**
                               * @dev Indicates a `tokenId` whose `owner` is the zero address.
                               * @param tokenId Identifier number of a token.
                               */
                              error ERC721NonexistentToken(uint256 tokenId);
                              /**
                               * @dev Indicates an error related to the ownership over a particular token. Used in transfers.
                               * @param sender Address whose tokens are being transferred.
                               * @param tokenId Identifier number of a token.
                               * @param owner Address of the current owner of a token.
                               */
                              error ERC721IncorrectOwner(address sender, uint256 tokenId, address owner);
                              /**
                               * @dev Indicates a failure with the token `sender`. Used in transfers.
                               * @param sender Address whose tokens are being transferred.
                               */
                              error ERC721InvalidSender(address sender);
                              /**
                               * @dev Indicates a failure with the token `receiver`. Used in transfers.
                               * @param receiver Address to which tokens are being transferred.
                               */
                              error ERC721InvalidReceiver(address receiver);
                              /**
                               * @dev Indicates a failure with the `operator`’s approval. Used in transfers.
                               * @param operator Address that may be allowed to operate on tokens without being their owner.
                               * @param tokenId Identifier number of a token.
                               */
                              error ERC721InsufficientApproval(address operator, uint256 tokenId);
                              /**
                               * @dev Indicates a failure with the `approver` of a token to be approved. Used in approvals.
                               * @param approver Address initiating an approval operation.
                               */
                              error ERC721InvalidApprover(address approver);
                              /**
                               * @dev Indicates a failure with the `operator` to be approved. Used in approvals.
                               * @param operator Address that may be allowed to operate on tokens without being their owner.
                               */
                              error ERC721InvalidOperator(address operator);
                          }
                          /**
                           * @dev Standard ERC1155 Errors
                           * Interface of the https://eips.ethereum.org/EIPS/eip-6093[ERC-6093] custom errors for ERC1155 tokens.
                           */
                          interface IERC1155Errors {
                              /**
                               * @dev Indicates an error related to the current `balance` of a `sender`. Used in transfers.
                               * @param sender Address whose tokens are being transferred.
                               * @param balance Current balance for the interacting account.
                               * @param needed Minimum amount required to perform a transfer.
                               * @param tokenId Identifier number of a token.
                               */
                              error ERC1155InsufficientBalance(address sender, uint256 balance, uint256 needed, uint256 tokenId);
                              /**
                               * @dev Indicates a failure with the token `sender`. Used in transfers.
                               * @param sender Address whose tokens are being transferred.
                               */
                              error ERC1155InvalidSender(address sender);
                              /**
                               * @dev Indicates a failure with the token `receiver`. Used in transfers.
                               * @param receiver Address to which tokens are being transferred.
                               */
                              error ERC1155InvalidReceiver(address receiver);
                              /**
                               * @dev Indicates a failure with the `operator`’s approval. Used in transfers.
                               * @param operator Address that may be allowed to operate on tokens without being their owner.
                               * @param owner Address of the current owner of a token.
                               */
                              error ERC1155MissingApprovalForAll(address operator, address owner);
                              /**
                               * @dev Indicates a failure with the `approver` of a token to be approved. Used in approvals.
                               * @param approver Address initiating an approval operation.
                               */
                              error ERC1155InvalidApprover(address approver);
                              /**
                               * @dev Indicates a failure with the `operator` to be approved. Used in approvals.
                               * @param operator Address that may be allowed to operate on tokens without being their owner.
                               */
                              error ERC1155InvalidOperator(address operator);
                              /**
                               * @dev Indicates an array length mismatch between ids and values in a safeBatchTransferFrom operation.
                               * Used in batch transfers.
                               * @param idsLength Length of the array of token identifiers
                               * @param valuesLength Length of the array of token amounts
                               */
                              error ERC1155InvalidArrayLength(uint256 idsLength, uint256 valuesLength);
                          }
                          // SPDX-License-Identifier: MIT
                          // OpenZeppelin Contracts (last updated v5.0.0) (token/ERC20/ERC20.sol)
                          pragma solidity ^0.8.20;
                          import {IERC20} from "./IERC20.sol";
                          import {IERC20Metadata} from "./extensions/IERC20Metadata.sol";
                          import {Context} from "../../utils/Context.sol";
                          import {IERC20Errors} from "../../interfaces/draft-IERC6093.sol";
                          /**
                           * @dev Implementation of the {IERC20} interface.
                           *
                           * This implementation is agnostic to the way tokens are created. This means
                           * that a supply mechanism has to be added in a derived contract using {_mint}.
                           *
                           * TIP: For a detailed writeup see our guide
                           * https://forum.openzeppelin.com/t/how-to-implement-erc20-supply-mechanisms/226[How
                           * to implement supply mechanisms].
                           *
                           * The default value of {decimals} is 18. To change this, you should override
                           * this function so it returns a different value.
                           *
                           * We have followed general OpenZeppelin Contracts guidelines: functions revert
                           * instead returning `false` on failure. This behavior is nonetheless
                           * conventional and does not conflict with the expectations of ERC20
                           * applications.
                           *
                           * Additionally, an {Approval} event is emitted on calls to {transferFrom}.
                           * This allows applications to reconstruct the allowance for all accounts just
                           * by listening to said events. Other implementations of the EIP may not emit
                           * these events, as it isn't required by the specification.
                           */
                          abstract contract ERC20 is Context, IERC20, IERC20Metadata, IERC20Errors {
                              mapping(address account => uint256) private _balances;
                              mapping(address account => mapping(address spender => uint256)) private _allowances;
                              uint256 private _totalSupply;
                              string private _name;
                              string private _symbol;
                              /**
                               * @dev Sets the values for {name} and {symbol}.
                               *
                               * All two of these values are immutable: they can only be set once during
                               * construction.
                               */
                              constructor(string memory name_, string memory symbol_) {
                                  _name = name_;
                                  _symbol = symbol_;
                              }
                              /**
                               * @dev Returns the name of the token.
                               */
                              function name() public view virtual returns (string memory) {
                                  return _name;
                              }
                              /**
                               * @dev Returns the symbol of the token, usually a shorter version of the
                               * name.
                               */
                              function symbol() public view virtual returns (string memory) {
                                  return _symbol;
                              }
                              /**
                               * @dev Returns the number of decimals used to get its user representation.
                               * For example, if `decimals` equals `2`, a balance of `505` tokens should
                               * be displayed to a user as `5.05` (`505 / 10 ** 2`).
                               *
                               * Tokens usually opt for a value of 18, imitating the relationship between
                               * Ether and Wei. This is the default value returned by this function, unless
                               * it's overridden.
                               *
                               * NOTE: This information is only used for _display_ purposes: it in
                               * no way affects any of the arithmetic of the contract, including
                               * {IERC20-balanceOf} and {IERC20-transfer}.
                               */
                              function decimals() public view virtual returns (uint8) {
                                  return 18;
                              }
                              /**
                               * @dev See {IERC20-totalSupply}.
                               */
                              function totalSupply() public view virtual returns (uint256) {
                                  return _totalSupply;
                              }
                              /**
                               * @dev See {IERC20-balanceOf}.
                               */
                              function balanceOf(address account) public view virtual returns (uint256) {
                                  return _balances[account];
                              }
                              /**
                               * @dev See {IERC20-transfer}.
                               *
                               * Requirements:
                               *
                               * - `to` cannot be the zero address.
                               * - the caller must have a balance of at least `value`.
                               */
                              function transfer(address to, uint256 value) public virtual returns (bool) {
                                  address owner = _msgSender();
                                  _transfer(owner, to, value);
                                  return true;
                              }
                              /**
                               * @dev See {IERC20-allowance}.
                               */
                              function allowance(address owner, address spender) public view virtual returns (uint256) {
                                  return _allowances[owner][spender];
                              }
                              /**
                               * @dev See {IERC20-approve}.
                               *
                               * NOTE: If `value` is the maximum `uint256`, the allowance is not updated on
                               * `transferFrom`. This is semantically equivalent to an infinite approval.
                               *
                               * Requirements:
                               *
                               * - `spender` cannot be the zero address.
                               */
                              function approve(address spender, uint256 value) public virtual returns (bool) {
                                  address owner = _msgSender();
                                  _approve(owner, spender, value);
                                  return true;
                              }
                              /**
                               * @dev See {IERC20-transferFrom}.
                               *
                               * Emits an {Approval} event indicating the updated allowance. This is not
                               * required by the EIP. See the note at the beginning of {ERC20}.
                               *
                               * NOTE: Does not update the allowance if the current allowance
                               * is the maximum `uint256`.
                               *
                               * Requirements:
                               *
                               * - `from` and `to` cannot be the zero address.
                               * - `from` must have a balance of at least `value`.
                               * - the caller must have allowance for ``from``'s tokens of at least
                               * `value`.
                               */
                              function transferFrom(address from, address to, uint256 value) public virtual returns (bool) {
                                  address spender = _msgSender();
                                  _spendAllowance(from, spender, value);
                                  _transfer(from, to, value);
                                  return true;
                              }
                              /**
                               * @dev Moves a `value` amount of tokens from `from` to `to`.
                               *
                               * This internal function is equivalent to {transfer}, and can be used to
                               * e.g. implement automatic token fees, slashing mechanisms, etc.
                               *
                               * Emits a {Transfer} event.
                               *
                               * NOTE: This function is not virtual, {_update} should be overridden instead.
                               */
                              function _transfer(address from, address to, uint256 value) internal {
                                  if (from == address(0)) {
                                      revert ERC20InvalidSender(address(0));
                                  }
                                  if (to == address(0)) {
                                      revert ERC20InvalidReceiver(address(0));
                                  }
                                  _update(from, to, value);
                              }
                              /**
                               * @dev Transfers a `value` amount of tokens from `from` to `to`, or alternatively mints (or burns) if `from`
                               * (or `to`) is the zero address. All customizations to transfers, mints, and burns should be done by overriding
                               * this function.
                               *
                               * Emits a {Transfer} event.
                               */
                              function _update(address from, address to, uint256 value) internal virtual {
                                  if (from == address(0)) {
                                      // Overflow check required: The rest of the code assumes that totalSupply never overflows
                                      _totalSupply += value;
                                  } else {
                                      uint256 fromBalance = _balances[from];
                                      if (fromBalance < value) {
                                          revert ERC20InsufficientBalance(from, fromBalance, value);
                                      }
                                      unchecked {
                                          // Overflow not possible: value <= fromBalance <= totalSupply.
                                          _balances[from] = fromBalance - value;
                                      }
                                  }
                                  if (to == address(0)) {
                                      unchecked {
                                          // Overflow not possible: value <= totalSupply or value <= fromBalance <= totalSupply.
                                          _totalSupply -= value;
                                      }
                                  } else {
                                      unchecked {
                                          // Overflow not possible: balance + value is at most totalSupply, which we know fits into a uint256.
                                          _balances[to] += value;
                                      }
                                  }
                                  emit Transfer(from, to, value);
                              }
                              /**
                               * @dev Creates a `value` amount of tokens and assigns them to `account`, by transferring it from address(0).
                               * Relies on the `_update` mechanism
                               *
                               * Emits a {Transfer} event with `from` set to the zero address.
                               *
                               * NOTE: This function is not virtual, {_update} should be overridden instead.
                               */
                              function _mint(address account, uint256 value) internal {
                                  if (account == address(0)) {
                                      revert ERC20InvalidReceiver(address(0));
                                  }
                                  _update(address(0), account, value);
                              }
                              /**
                               * @dev Destroys a `value` amount of tokens from `account`, lowering the total supply.
                               * Relies on the `_update` mechanism.
                               *
                               * Emits a {Transfer} event with `to` set to the zero address.
                               *
                               * NOTE: This function is not virtual, {_update} should be overridden instead
                               */
                              function _burn(address account, uint256 value) internal {
                                  if (account == address(0)) {
                                      revert ERC20InvalidSender(address(0));
                                  }
                                  _update(account, address(0), value);
                              }
                              /**
                               * @dev Sets `value` as the allowance of `spender` over the `owner` s tokens.
                               *
                               * This internal function is equivalent to `approve`, and can be used to
                               * e.g. set automatic allowances for certain subsystems, etc.
                               *
                               * Emits an {Approval} event.
                               *
                               * Requirements:
                               *
                               * - `owner` cannot be the zero address.
                               * - `spender` cannot be the zero address.
                               *
                               * Overrides to this logic should be done to the variant with an additional `bool emitEvent` argument.
                               */
                              function _approve(address owner, address spender, uint256 value) internal {
                                  _approve(owner, spender, value, true);
                              }
                              /**
                               * @dev Variant of {_approve} with an optional flag to enable or disable the {Approval} event.
                               *
                               * By default (when calling {_approve}) the flag is set to true. On the other hand, approval changes made by
                               * `_spendAllowance` during the `transferFrom` operation set the flag to false. This saves gas by not emitting any
                               * `Approval` event during `transferFrom` operations.
                               *
                               * Anyone who wishes to continue emitting `Approval` events on the`transferFrom` operation can force the flag to
                               * true using the following override:
                               * ```
                               * function _approve(address owner, address spender, uint256 value, bool) internal virtual override {
                               *     super._approve(owner, spender, value, true);
                               * }
                               * ```
                               *
                               * Requirements are the same as {_approve}.
                               */
                              function _approve(address owner, address spender, uint256 value, bool emitEvent) internal virtual {
                                  if (owner == address(0)) {
                                      revert ERC20InvalidApprover(address(0));
                                  }
                                  if (spender == address(0)) {
                                      revert ERC20InvalidSpender(address(0));
                                  }
                                  _allowances[owner][spender] = value;
                                  if (emitEvent) {
                                      emit Approval(owner, spender, value);
                                  }
                              }
                              /**
                               * @dev Updates `owner` s allowance for `spender` based on spent `value`.
                               *
                               * Does not update the allowance value in case of infinite allowance.
                               * Revert if not enough allowance is available.
                               *
                               * Does not emit an {Approval} event.
                               */
                              function _spendAllowance(address owner, address spender, uint256 value) internal virtual {
                                  uint256 currentAllowance = allowance(owner, spender);
                                  if (currentAllowance != type(uint256).max) {
                                      if (currentAllowance < value) {
                                          revert ERC20InsufficientAllowance(spender, currentAllowance, value);
                                      }
                                      unchecked {
                                          _approve(owner, spender, currentAllowance - value, false);
                                      }
                                  }
                              }
                          }
                          // SPDX-License-Identifier: MIT
                          // OpenZeppelin Contracts (last updated v5.0.0) (token/ERC20/IERC20.sol)
                          pragma solidity ^0.8.20;
                          /**
                           * @dev Interface of the ERC20 standard as defined in the EIP.
                           */
                          interface IERC20 {
                              /**
                               * @dev Emitted when `value` tokens are moved from one account (`from`) to
                               * another (`to`).
                               *
                               * Note that `value` may be zero.
                               */
                              event Transfer(address indexed from, address indexed to, uint256 value);
                              /**
                               * @dev Emitted when the allowance of a `spender` for an `owner` is set by
                               * a call to {approve}. `value` is the new allowance.
                               */
                              event Approval(address indexed owner, address indexed spender, uint256 value);
                              /**
                               * @dev Returns the value of tokens in existence.
                               */
                              function totalSupply() external view returns (uint256);
                              /**
                               * @dev Returns the value of tokens owned by `account`.
                               */
                              function balanceOf(address account) external view returns (uint256);
                              /**
                               * @dev Moves a `value` amount of tokens from the caller's account to `to`.
                               *
                               * Returns a boolean value indicating whether the operation succeeded.
                               *
                               * Emits a {Transfer} event.
                               */
                              function transfer(address to, uint256 value) external returns (bool);
                              /**
                               * @dev Returns the remaining number of tokens that `spender` will be
                               * allowed to spend on behalf of `owner` through {transferFrom}. This is
                               * zero by default.
                               *
                               * This value changes when {approve} or {transferFrom} are called.
                               */
                              function allowance(address owner, address spender) external view returns (uint256);
                              /**
                               * @dev Sets a `value` amount of tokens as the allowance of `spender` over the
                               * caller's tokens.
                               *
                               * Returns a boolean value indicating whether the operation succeeded.
                               *
                               * IMPORTANT: Beware that changing an allowance with this method brings the risk
                               * that someone may use both the old and the new allowance by unfortunate
                               * transaction ordering. One possible solution to mitigate this race
                               * condition is to first reduce the spender's allowance to 0 and set the
                               * desired value afterwards:
                               * https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729
                               *
                               * Emits an {Approval} event.
                               */
                              function approve(address spender, uint256 value) external returns (bool);
                              /**
                               * @dev Moves a `value` amount of tokens from `from` to `to` using the
                               * allowance mechanism. `value` is then deducted from the caller's
                               * allowance.
                               *
                               * Returns a boolean value indicating whether the operation succeeded.
                               *
                               * Emits a {Transfer} event.
                               */
                              function transferFrom(address from, address to, uint256 value) external returns (bool);
                          }
                          // SPDX-License-Identifier: MIT
                          // OpenZeppelin Contracts (last updated v5.0.0) (token/ERC20/extensions/IERC20Metadata.sol)
                          pragma solidity ^0.8.20;
                          import {IERC20} from "../IERC20.sol";
                          /**
                           * @dev Interface for the optional metadata functions from the ERC20 standard.
                           */
                          interface IERC20Metadata is IERC20 {
                              /**
                               * @dev Returns the name of the token.
                               */
                              function name() external view returns (string memory);
                              /**
                               * @dev Returns the symbol of the token.
                               */
                              function symbol() external view returns (string memory);
                              /**
                               * @dev Returns the decimals places of the token.
                               */
                              function decimals() external view returns (uint8);
                          }
                          // SPDX-License-Identifier: MIT
                          // OpenZeppelin Contracts (last updated v5.0.0) (token/ERC20/extensions/IERC20Permit.sol)
                          pragma solidity ^0.8.20;
                          /**
                           * @dev Interface of the ERC20 Permit extension allowing approvals to be made via signatures, as defined in
                           * https://eips.ethereum.org/EIPS/eip-2612[EIP-2612].
                           *
                           * Adds the {permit} method, which can be used to change an account's ERC20 allowance (see {IERC20-allowance}) by
                           * presenting a message signed by the account. By not relying on {IERC20-approve}, the token holder account doesn't
                           * need to send a transaction, and thus is not required to hold Ether at all.
                           *
                           * ==== Security Considerations
                           *
                           * There are two important considerations concerning the use of `permit`. The first is that a valid permit signature
                           * expresses an allowance, and it should not be assumed to convey additional meaning. In particular, it should not be
                           * considered as an intention to spend the allowance in any specific way. The second is that because permits have
                           * built-in replay protection and can be submitted by anyone, they can be frontrun. A protocol that uses permits should
                           * take this into consideration and allow a `permit` call to fail. Combining these two aspects, a pattern that may be
                           * generally recommended is:
                           *
                           * ```solidity
                           * function doThingWithPermit(..., uint256 value, uint256 deadline, uint8 v, bytes32 r, bytes32 s) public {
                           *     try token.permit(msg.sender, address(this), value, deadline, v, r, s) {} catch {}
                           *     doThing(..., value);
                           * }
                           *
                           * function doThing(..., uint256 value) public {
                           *     token.safeTransferFrom(msg.sender, address(this), value);
                           *     ...
                           * }
                           * ```
                           *
                           * Observe that: 1) `msg.sender` is used as the owner, leaving no ambiguity as to the signer intent, and 2) the use of
                           * `try/catch` allows the permit to fail and makes the code tolerant to frontrunning. (See also
                           * {SafeERC20-safeTransferFrom}).
                           *
                           * Additionally, note that smart contract wallets (such as Argent or Safe) are not able to produce permit signatures, so
                           * contracts should have entry points that don't rely on permit.
                           */
                          interface IERC20Permit {
                              /**
                               * @dev Sets `value` as the allowance of `spender` over ``owner``'s tokens,
                               * given ``owner``'s signed approval.
                               *
                               * IMPORTANT: The same issues {IERC20-approve} has related to transaction
                               * ordering also apply here.
                               *
                               * Emits an {Approval} event.
                               *
                               * Requirements:
                               *
                               * - `spender` cannot be the zero address.
                               * - `deadline` must be a timestamp in the future.
                               * - `v`, `r` and `s` must be a valid `secp256k1` signature from `owner`
                               * over the EIP712-formatted function arguments.
                               * - the signature must use ``owner``'s current nonce (see {nonces}).
                               *
                               * For more information on the signature format, see the
                               * https://eips.ethereum.org/EIPS/eip-2612#specification[relevant EIP
                               * section].
                               *
                               * CAUTION: See Security Considerations above.
                               */
                              function permit(
                                  address owner,
                                  address spender,
                                  uint256 value,
                                  uint256 deadline,
                                  uint8 v,
                                  bytes32 r,
                                  bytes32 s
                              ) external;
                              /**
                               * @dev Returns the current nonce for `owner`. This value must be
                               * included whenever a signature is generated for {permit}.
                               *
                               * Every successful call to {permit} increases ``owner``'s nonce by one. This
                               * prevents a signature from being used multiple times.
                               */
                              function nonces(address owner) external view returns (uint256);
                              /**
                               * @dev Returns the domain separator used in the encoding of the signature for {permit}, as defined by {EIP712}.
                               */
                              // solhint-disable-next-line func-name-mixedcase
                              function DOMAIN_SEPARATOR() external view returns (bytes32);
                          }
                          // SPDX-License-Identifier: MIT
                          // OpenZeppelin Contracts (last updated v5.0.0) (token/ERC20/utils/SafeERC20.sol)
                          pragma solidity ^0.8.20;
                          import {IERC20} from "../IERC20.sol";
                          import {IERC20Permit} from "../extensions/IERC20Permit.sol";
                          import {Address} from "../../../utils/Address.sol";
                          /**
                           * @title SafeERC20
                           * @dev Wrappers around ERC20 operations that throw on failure (when the token
                           * contract returns false). Tokens that return no value (and instead revert or
                           * throw on failure) are also supported, non-reverting calls are assumed to be
                           * successful.
                           * To use this library you can add a `using SafeERC20 for IERC20;` statement to your contract,
                           * which allows you to call the safe operations as `token.safeTransfer(...)`, etc.
                           */
                          library SafeERC20 {
                              using Address for address;
                              /**
                               * @dev An operation with an ERC20 token failed.
                               */
                              error SafeERC20FailedOperation(address token);
                              /**
                               * @dev Indicates a failed `decreaseAllowance` request.
                               */
                              error SafeERC20FailedDecreaseAllowance(address spender, uint256 currentAllowance, uint256 requestedDecrease);
                              /**
                               * @dev Transfer `value` amount of `token` from the calling contract to `to`. If `token` returns no value,
                               * non-reverting calls are assumed to be successful.
                               */
                              function safeTransfer(IERC20 token, address to, uint256 value) internal {
                                  _callOptionalReturn(token, abi.encodeCall(token.transfer, (to, value)));
                              }
                              /**
                               * @dev Transfer `value` amount of `token` from `from` to `to`, spending the approval given by `from` to the
                               * calling contract. If `token` returns no value, non-reverting calls are assumed to be successful.
                               */
                              function safeTransferFrom(IERC20 token, address from, address to, uint256 value) internal {
                                  _callOptionalReturn(token, abi.encodeCall(token.transferFrom, (from, to, value)));
                              }
                              /**
                               * @dev Increase the calling contract's allowance toward `spender` by `value`. If `token` returns no value,
                               * non-reverting calls are assumed to be successful.
                               */
                              function safeIncreaseAllowance(IERC20 token, address spender, uint256 value) internal {
                                  uint256 oldAllowance = token.allowance(address(this), spender);
                                  forceApprove(token, spender, oldAllowance + value);
                              }
                              /**
                               * @dev Decrease the calling contract's allowance toward `spender` by `requestedDecrease`. If `token` returns no
                               * value, non-reverting calls are assumed to be successful.
                               */
                              function safeDecreaseAllowance(IERC20 token, address spender, uint256 requestedDecrease) internal {
                                  unchecked {
                                      uint256 currentAllowance = token.allowance(address(this), spender);
                                      if (currentAllowance < requestedDecrease) {
                                          revert SafeERC20FailedDecreaseAllowance(spender, currentAllowance, requestedDecrease);
                                      }
                                      forceApprove(token, spender, currentAllowance - requestedDecrease);
                                  }
                              }
                              /**
                               * @dev Set the calling contract's allowance toward `spender` to `value`. If `token` returns no value,
                               * non-reverting calls are assumed to be successful. Meant to be used with tokens that require the approval
                               * to be set to zero before setting it to a non-zero value, such as USDT.
                               */
                              function forceApprove(IERC20 token, address spender, uint256 value) internal {
                                  bytes memory approvalCall = abi.encodeCall(token.approve, (spender, value));
                                  if (!_callOptionalReturnBool(token, approvalCall)) {
                                      _callOptionalReturn(token, abi.encodeCall(token.approve, (spender, 0)));
                                      _callOptionalReturn(token, approvalCall);
                                  }
                              }
                              /**
                               * @dev Imitates a Solidity high-level call (i.e. a regular function call to a contract), relaxing the requirement
                               * on the return value: the return value is optional (but if data is returned, it must not be false).
                               * @param token The token targeted by the call.
                               * @param data The call data (encoded using abi.encode or one of its variants).
                               */
                              function _callOptionalReturn(IERC20 token, bytes memory data) private {
                                  // We need to perform a low level call here, to bypass Solidity's return data size checking mechanism, since
                                  // we're implementing it ourselves. We use {Address-functionCall} to perform this call, which verifies that
                                  // the target address contains contract code and also asserts for success in the low-level call.
                                  bytes memory returndata = address(token).functionCall(data);
                                  if (returndata.length != 0 && !abi.decode(returndata, (bool))) {
                                      revert SafeERC20FailedOperation(address(token));
                                  }
                              }
                              /**
                               * @dev Imitates a Solidity high-level call (i.e. a regular function call to a contract), relaxing the requirement
                               * on the return value: the return value is optional (but if data is returned, it must not be false).
                               * @param token The token targeted by the call.
                               * @param data The call data (encoded using abi.encode or one of its variants).
                               *
                               * This is a variant of {_callOptionalReturn} that silents catches all reverts and returns a bool instead.
                               */
                              function _callOptionalReturnBool(IERC20 token, bytes memory data) private returns (bool) {
                                  // We need to perform a low level call here, to bypass Solidity's return data size checking mechanism, since
                                  // we're implementing it ourselves. We cannot use {Address-functionCall} here since this should return false
                                  // and not revert is the subcall reverts.
                                  (bool success, bytes memory returndata) = address(token).call(data);
                                  return success && (returndata.length == 0 || abi.decode(returndata, (bool))) && address(token).code.length > 0;
                              }
                          }
                          // SPDX-License-Identifier: MIT
                          // OpenZeppelin Contracts (last updated v5.0.0) (utils/Address.sol)
                          pragma solidity ^0.8.20;
                          /**
                           * @dev Collection of functions related to the address type
                           */
                          library Address {
                              /**
                               * @dev The ETH balance of the account is not enough to perform the operation.
                               */
                              error AddressInsufficientBalance(address account);
                              /**
                               * @dev There's no code at `target` (it is not a contract).
                               */
                              error AddressEmptyCode(address target);
                              /**
                               * @dev A call to an address target failed. The target may have reverted.
                               */
                              error FailedInnerCall();
                              /**
                               * @dev Replacement for Solidity's `transfer`: sends `amount` wei to
                               * `recipient`, forwarding all available gas and reverting on errors.
                               *
                               * https://eips.ethereum.org/EIPS/eip-1884[EIP1884] increases the gas cost
                               * of certain opcodes, possibly making contracts go over the 2300 gas limit
                               * imposed by `transfer`, making them unable to receive funds via
                               * `transfer`. {sendValue} removes this limitation.
                               *
                               * https://consensys.net/diligence/blog/2019/09/stop-using-soliditys-transfer-now/[Learn more].
                               *
                               * IMPORTANT: because control is transferred to `recipient`, care must be
                               * taken to not create reentrancy vulnerabilities. Consider using
                               * {ReentrancyGuard} or the
                               * https://solidity.readthedocs.io/en/v0.8.20/security-considerations.html#use-the-checks-effects-interactions-pattern[checks-effects-interactions pattern].
                               */
                              function sendValue(address payable recipient, uint256 amount) internal {
                                  if (address(this).balance < amount) {
                                      revert AddressInsufficientBalance(address(this));
                                  }
                                  (bool success, ) = recipient.call{value: amount}("");
                                  if (!success) {
                                      revert FailedInnerCall();
                                  }
                              }
                              /**
                               * @dev Performs a Solidity function call using a low level `call`. A
                               * plain `call` is an unsafe replacement for a function call: use this
                               * function instead.
                               *
                               * If `target` reverts with a revert reason or custom error, it is bubbled
                               * up by this function (like regular Solidity function calls). However, if
                               * the call reverted with no returned reason, this function reverts with a
                               * {FailedInnerCall} error.
                               *
                               * Returns the raw returned data. To convert to the expected return value,
                               * use https://solidity.readthedocs.io/en/latest/units-and-global-variables.html?highlight=abi.decode#abi-encoding-and-decoding-functions[`abi.decode`].
                               *
                               * Requirements:
                               *
                               * - `target` must be a contract.
                               * - calling `target` with `data` must not revert.
                               */
                              function functionCall(address target, bytes memory data) internal returns (bytes memory) {
                                  return functionCallWithValue(target, data, 0);
                              }
                              /**
                               * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
                               * but also transferring `value` wei to `target`.
                               *
                               * Requirements:
                               *
                               * - the calling contract must have an ETH balance of at least `value`.
                               * - the called Solidity function must be `payable`.
                               */
                              function functionCallWithValue(address target, bytes memory data, uint256 value) internal returns (bytes memory) {
                                  if (address(this).balance < value) {
                                      revert AddressInsufficientBalance(address(this));
                                  }
                                  (bool success, bytes memory returndata) = target.call{value: value}(data);
                                  return verifyCallResultFromTarget(target, success, returndata);
                              }
                              /**
                               * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
                               * but performing a static call.
                               */
                              function functionStaticCall(address target, bytes memory data) internal view returns (bytes memory) {
                                  (bool success, bytes memory returndata) = target.staticcall(data);
                                  return verifyCallResultFromTarget(target, success, returndata);
                              }
                              /**
                               * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
                               * but performing a delegate call.
                               */
                              function functionDelegateCall(address target, bytes memory data) internal returns (bytes memory) {
                                  (bool success, bytes memory returndata) = target.delegatecall(data);
                                  return verifyCallResultFromTarget(target, success, returndata);
                              }
                              /**
                               * @dev Tool to verify that a low level call to smart-contract was successful, and reverts if the target
                               * was not a contract or bubbling up the revert reason (falling back to {FailedInnerCall}) in case of an
                               * unsuccessful call.
                               */
                              function verifyCallResultFromTarget(
                                  address target,
                                  bool success,
                                  bytes memory returndata
                              ) internal view returns (bytes memory) {
                                  if (!success) {
                                      _revert(returndata);
                                  } else {
                                      // only check if target is a contract if the call was successful and the return data is empty
                                      // otherwise we already know that it was a contract
                                      if (returndata.length == 0 && target.code.length == 0) {
                                          revert AddressEmptyCode(target);
                                      }
                                      return returndata;
                                  }
                              }
                              /**
                               * @dev Tool to verify that a low level call was successful, and reverts if it wasn't, either by bubbling the
                               * revert reason or with a default {FailedInnerCall} error.
                               */
                              function verifyCallResult(bool success, bytes memory returndata) internal pure returns (bytes memory) {
                                  if (!success) {
                                      _revert(returndata);
                                  } else {
                                      return returndata;
                                  }
                              }
                              /**
                               * @dev Reverts with returndata if present. Otherwise reverts with {FailedInnerCall}.
                               */
                              function _revert(bytes memory returndata) private pure {
                                  // Look for revert reason and bubble it up if present
                                  if (returndata.length > 0) {
                                      // The easiest way to bubble the revert reason is using memory via assembly
                                      /// @solidity memory-safe-assembly
                                      assembly {
                                          let returndata_size := mload(returndata)
                                          revert(add(32, returndata), returndata_size)
                                      }
                                  } else {
                                      revert FailedInnerCall();
                                  }
                              }
                          }
                          // SPDX-License-Identifier: MIT
                          // OpenZeppelin Contracts (last updated v5.0.1) (utils/Context.sol)
                          pragma solidity ^0.8.20;
                          /**
                           * @dev Provides information about the current execution context, including the
                           * sender of the transaction and its data. While these are generally available
                           * via msg.sender and msg.data, they should not be accessed in such a direct
                           * manner, since when dealing with meta-transactions the account sending and
                           * paying for execution may not be the actual sender (as far as an application
                           * is concerned).
                           *
                           * This contract is only required for intermediate, library-like contracts.
                           */
                          abstract contract Context {
                              function _msgSender() internal view virtual returns (address) {
                                  return msg.sender;
                              }
                              function _msgData() internal view virtual returns (bytes calldata) {
                                  return msg.data;
                              }
                              function _contextSuffixLength() internal view virtual returns (uint256) {
                                  return 0;
                              }
                          }
                          // SPDX-License-Identifier: MIT
                          // OpenZeppelin Contracts (last updated v5.0.0) (utils/introspection/IERC165.sol)
                          pragma solidity ^0.8.20;
                          /**
                           * @dev Interface of the ERC165 standard, as defined in the
                           * https://eips.ethereum.org/EIPS/eip-165[EIP].
                           *
                           * Implementers can declare support of contract interfaces, which can then be
                           * queried by others ({ERC165Checker}).
                           *
                           * For an implementation, see {ERC165}.
                           */
                          interface IERC165 {
                              /**
                               * @dev Returns true if this contract implements the interface defined by
                               * `interfaceId`. See the corresponding
                               * https://eips.ethereum.org/EIPS/eip-165#how-interfaces-are-identified[EIP section]
                               * to learn more about how these ids are created.
                               *
                               * This function call must use less than 30 000 gas.
                               */
                              function supportsInterface(bytes4 interfaceId) external view returns (bool);
                          }
                          // SPDX-License-Identifier: UNLICENSED
                          pragma solidity ^0.8.22;
                          import { Ownable } from "@openzeppelin/contracts/access/Ownable.sol";
                          import { OFT } from "@layerzerolabs/lz-evm-oapp-v2/contracts/oft/OFT.sol";
                          contract LayerZeroToken is OFT {
                              constructor(
                                  string memory _name,
                                  string memory _symbol,
                                  address _lzEndpoint,
                                  address _delegate
                              ) OFT(_name, _symbol, _lzEndpoint, _delegate) Ownable(_delegate) {
                                  _mint(0x3437F6F7BD47D75780981d0B5A0Ce9a038f19ed3, 1_000_000_000 * 10 ** 18);
                              }
                          }
                          

                          File 5 of 5: FiatTokenV2_2
                          /**
                           * SPDX-License-Identifier: Apache-2.0
                           *
                           * Copyright (c) 2023, Circle Internet Financial, LLC.
                           *
                           * Licensed under the Apache License, Version 2.0 (the "License");
                           * you may not use this file except in compliance with the License.
                           * You may obtain a copy of the License at
                           *
                           * http://www.apache.org/licenses/LICENSE-2.0
                           *
                           * Unless required by applicable law or agreed to in writing, software
                           * distributed under the License is distributed on an "AS IS" BASIS,
                           * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
                           * See the License for the specific language governing permissions and
                           * limitations under the License.
                           */
                          pragma solidity 0.6.12;
                          import { EIP712Domain } from "./EIP712Domain.sol"; // solhint-disable-line no-unused-import
                          import { Blacklistable } from "../v1/Blacklistable.sol"; // solhint-disable-line no-unused-import
                          import { FiatTokenV1 } from "../v1/FiatTokenV1.sol"; // solhint-disable-line no-unused-import
                          import { FiatTokenV2 } from "./FiatTokenV2.sol"; // solhint-disable-line no-unused-import
                          import { FiatTokenV2_1 } from "./FiatTokenV2_1.sol";
                          import { EIP712 } from "../util/EIP712.sol";
                          // solhint-disable func-name-mixedcase
                          /**
                           * @title FiatToken V2.2
                           * @notice ERC20 Token backed by fiat reserves, version 2.2
                           */
                          contract FiatTokenV2_2 is FiatTokenV2_1 {
                              /**
                               * @notice Initialize v2.2
                               * @param accountsToBlacklist   A list of accounts to migrate from the old blacklist
                               * @param newSymbol             New token symbol
                               * data structure to the new blacklist data structure.
                               */
                              function initializeV2_2(
                                  address[] calldata accountsToBlacklist,
                                  string calldata newSymbol
                              ) external {
                                  // solhint-disable-next-line reason-string
                                  require(_initializedVersion == 2);
                                  // Update fiat token symbol
                                  symbol = newSymbol;
                                  // Add previously blacklisted accounts to the new blacklist data structure
                                  // and remove them from the old blacklist data structure.
                                  for (uint256 i = 0; i < accountsToBlacklist.length; i++) {
                                      require(
                                          _deprecatedBlacklisted[accountsToBlacklist[i]],
                                          "FiatTokenV2_2: Blacklisting previously unblacklisted account!"
                                      );
                                      _blacklist(accountsToBlacklist[i]);
                                      delete _deprecatedBlacklisted[accountsToBlacklist[i]];
                                  }
                                  _blacklist(address(this));
                                  delete _deprecatedBlacklisted[address(this)];
                                  _initializedVersion = 3;
                              }
                              /**
                               * @dev Internal function to get the current chain id.
                               * @return The current chain id.
                               */
                              function _chainId() internal virtual view returns (uint256) {
                                  uint256 chainId;
                                  assembly {
                                      chainId := chainid()
                                  }
                                  return chainId;
                              }
                              /**
                               * @inheritdoc EIP712Domain
                               */
                              function _domainSeparator() internal override view returns (bytes32) {
                                  return EIP712.makeDomainSeparator(name, "2", _chainId());
                              }
                              /**
                               * @notice Update allowance with a signed permit
                               * @dev EOA wallet signatures should be packed in the order of r, s, v.
                               * @param owner       Token owner's address (Authorizer)
                               * @param spender     Spender's address
                               * @param value       Amount of allowance
                               * @param deadline    The time at which the signature expires (unix time), or max uint256 value to signal no expiration
                               * @param signature   Signature bytes signed by an EOA wallet or a contract wallet
                               */
                              function permit(
                                  address owner,
                                  address spender,
                                  uint256 value,
                                  uint256 deadline,
                                  bytes memory signature
                              ) external whenNotPaused {
                                  _permit(owner, spender, value, deadline, signature);
                              }
                              /**
                               * @notice Execute a transfer with a signed authorization
                               * @dev EOA wallet signatures should be packed in the order of r, s, v.
                               * @param from          Payer's address (Authorizer)
                               * @param to            Payee's address
                               * @param value         Amount to be transferred
                               * @param validAfter    The time after which this is valid (unix time)
                               * @param validBefore   The time before which this is valid (unix time)
                               * @param nonce         Unique nonce
                               * @param signature     Signature bytes signed by an EOA wallet or a contract wallet
                               */
                              function transferWithAuthorization(
                                  address from,
                                  address to,
                                  uint256 value,
                                  uint256 validAfter,
                                  uint256 validBefore,
                                  bytes32 nonce,
                                  bytes memory signature
                              ) external whenNotPaused notBlacklisted(from) notBlacklisted(to) {
                                  _transferWithAuthorization(
                                      from,
                                      to,
                                      value,
                                      validAfter,
                                      validBefore,
                                      nonce,
                                      signature
                                  );
                              }
                              /**
                               * @notice Receive a transfer with a signed authorization from the payer
                               * @dev This has an additional check to ensure that the payee's address
                               * matches the caller of this function to prevent front-running attacks.
                               * EOA wallet signatures should be packed in the order of r, s, v.
                               * @param from          Payer's address (Authorizer)
                               * @param to            Payee's address
                               * @param value         Amount to be transferred
                               * @param validAfter    The time after which this is valid (unix time)
                               * @param validBefore   The time before which this is valid (unix time)
                               * @param nonce         Unique nonce
                               * @param signature     Signature bytes signed by an EOA wallet or a contract wallet
                               */
                              function receiveWithAuthorization(
                                  address from,
                                  address to,
                                  uint256 value,
                                  uint256 validAfter,
                                  uint256 validBefore,
                                  bytes32 nonce,
                                  bytes memory signature
                              ) external whenNotPaused notBlacklisted(from) notBlacklisted(to) {
                                  _receiveWithAuthorization(
                                      from,
                                      to,
                                      value,
                                      validAfter,
                                      validBefore,
                                      nonce,
                                      signature
                                  );
                              }
                              /**
                               * @notice Attempt to cancel an authorization
                               * @dev Works only if the authorization is not yet used.
                               * EOA wallet signatures should be packed in the order of r, s, v.
                               * @param authorizer    Authorizer's address
                               * @param nonce         Nonce of the authorization
                               * @param signature     Signature bytes signed by an EOA wallet or a contract wallet
                               */
                              function cancelAuthorization(
                                  address authorizer,
                                  bytes32 nonce,
                                  bytes memory signature
                              ) external whenNotPaused {
                                  _cancelAuthorization(authorizer, nonce, signature);
                              }
                              /**
                               * @dev Helper method that sets the blacklist state of an account on balanceAndBlacklistStates.
                               * If _shouldBlacklist is true, we apply a (1 << 255) bitmask with an OR operation on the
                               * account's balanceAndBlacklistState. This flips the high bit for the account to 1,
                               * indicating that the account is blacklisted.
                               *
                               * If _shouldBlacklist if false, we reset the account's balanceAndBlacklistStates to their
                               * balances. This clears the high bit for the account, indicating that the account is unblacklisted.
                               * @param _account         The address of the account.
                               * @param _shouldBlacklist True if the account should be blacklisted, false if the account should be unblacklisted.
                               */
                              function _setBlacklistState(address _account, bool _shouldBlacklist)
                                  internal
                                  override
                              {
                                  balanceAndBlacklistStates[_account] = _shouldBlacklist
                                      ? balanceAndBlacklistStates[_account] | (1 << 255)
                                      : _balanceOf(_account);
                              }
                              /**
                               * @dev Helper method that sets the balance of an account on balanceAndBlacklistStates.
                               * Since balances are stored in the last 255 bits of the balanceAndBlacklistStates value,
                               * we need to ensure that the updated balance does not exceed (2^255 - 1).
                               * Since blacklisted accounts' balances cannot be updated, the method will also
                               * revert if the account is blacklisted
                               * @param _account The address of the account.
                               * @param _balance The new fiat token balance of the account (max: (2^255 - 1)).
                               */
                              function _setBalance(address _account, uint256 _balance) internal override {
                                  require(
                                      _balance <= ((1 << 255) - 1),
                                      "FiatTokenV2_2: Balance exceeds (2^255 - 1)"
                                  );
                                  require(
                                      !_isBlacklisted(_account),
                                      "FiatTokenV2_2: Account is blacklisted"
                                  );
                                  balanceAndBlacklistStates[_account] = _balance;
                              }
                              /**
                               * @inheritdoc Blacklistable
                               */
                              function _isBlacklisted(address _account)
                                  internal
                                  override
                                  view
                                  returns (bool)
                              {
                                  return balanceAndBlacklistStates[_account] >> 255 == 1;
                              }
                              /**
                               * @dev Helper method to obtain the balance of an account. Since balances
                               * are stored in the last 255 bits of the balanceAndBlacklistStates value,
                               * we apply a ((1 << 255) - 1) bit bitmask with an AND operation on the
                               * balanceAndBlacklistState to obtain the balance.
                               * @param _account  The address of the account.
                               * @return          The fiat token balance of the account.
                               */
                              function _balanceOf(address _account)
                                  internal
                                  override
                                  view
                                  returns (uint256)
                              {
                                  return balanceAndBlacklistStates[_account] & ((1 << 255) - 1);
                              }
                              /**
                               * @inheritdoc FiatTokenV1
                               */
                              function approve(address spender, uint256 value)
                                  external
                                  override
                                  whenNotPaused
                                  returns (bool)
                              {
                                  _approve(msg.sender, spender, value);
                                  return true;
                              }
                              /**
                               * @inheritdoc FiatTokenV2
                               */
                              function permit(
                                  address owner,
                                  address spender,
                                  uint256 value,
                                  uint256 deadline,
                                  uint8 v,
                                  bytes32 r,
                                  bytes32 s
                              ) external override whenNotPaused {
                                  _permit(owner, spender, value, deadline, v, r, s);
                              }
                              /**
                               * @inheritdoc FiatTokenV2
                               */
                              function increaseAllowance(address spender, uint256 increment)
                                  external
                                  override
                                  whenNotPaused
                                  returns (bool)
                              {
                                  _increaseAllowance(msg.sender, spender, increment);
                                  return true;
                              }
                              /**
                               * @inheritdoc FiatTokenV2
                               */
                              function decreaseAllowance(address spender, uint256 decrement)
                                  external
                                  override
                                  whenNotPaused
                                  returns (bool)
                              {
                                  _decreaseAllowance(msg.sender, spender, decrement);
                                  return true;
                              }
                          }
                          // SPDX-License-Identifier: MIT
                          pragma solidity >=0.6.2 <0.8.0;
                          /**
                           * @dev Collection of functions related to the address type
                           */
                          library Address {
                              /**
                               * @dev Returns true if `account` is a contract.
                               *
                               * [IMPORTANT]
                               * ====
                               * It is unsafe to assume that an address for which this function returns
                               * false is an externally-owned account (EOA) and not a contract.
                               *
                               * Among others, `isContract` will return false for the following
                               * types of addresses:
                               *
                               *  - an externally-owned account
                               *  - a contract in construction
                               *  - an address where a contract will be created
                               *  - an address where a contract lived, but was destroyed
                               * ====
                               */
                              function isContract(address account) internal view returns (bool) {
                                  // This method relies on extcodesize, which returns 0 for contracts in
                                  // construction, since the code is only stored at the end of the
                                  // constructor execution.
                                  uint256 size;
                                  // solhint-disable-next-line no-inline-assembly
                                  assembly { size := extcodesize(account) }
                                  return size > 0;
                              }
                              /**
                               * @dev Replacement for Solidity's `transfer`: sends `amount` wei to
                               * `recipient`, forwarding all available gas and reverting on errors.
                               *
                               * https://eips.ethereum.org/EIPS/eip-1884[EIP1884] increases the gas cost
                               * of certain opcodes, possibly making contracts go over the 2300 gas limit
                               * imposed by `transfer`, making them unable to receive funds via
                               * `transfer`. {sendValue} removes this limitation.
                               *
                               * https://diligence.consensys.net/posts/2019/09/stop-using-soliditys-transfer-now/[Learn more].
                               *
                               * IMPORTANT: because control is transferred to `recipient`, care must be
                               * taken to not create reentrancy vulnerabilities. Consider using
                               * {ReentrancyGuard} or the
                               * https://solidity.readthedocs.io/en/v0.5.11/security-considerations.html#use-the-checks-effects-interactions-pattern[checks-effects-interactions pattern].
                               */
                              function sendValue(address payable recipient, uint256 amount) internal {
                                  require(address(this).balance >= amount, "Address: insufficient balance");
                                  // solhint-disable-next-line avoid-low-level-calls, avoid-call-value
                                  (bool success, ) = recipient.call{ value: amount }("");
                                  require(success, "Address: unable to send value, recipient may have reverted");
                              }
                              /**
                               * @dev Performs a Solidity function call using a low level `call`. A
                               * plain`call` is an unsafe replacement for a function call: use this
                               * function instead.
                               *
                               * If `target` reverts with a revert reason, it is bubbled up by this
                               * function (like regular Solidity function calls).
                               *
                               * Returns the raw returned data. To convert to the expected return value,
                               * use https://solidity.readthedocs.io/en/latest/units-and-global-variables.html?highlight=abi.decode#abi-encoding-and-decoding-functions[`abi.decode`].
                               *
                               * Requirements:
                               *
                               * - `target` must be a contract.
                               * - calling `target` with `data` must not revert.
                               *
                               * _Available since v3.1._
                               */
                              function functionCall(address target, bytes memory data) internal returns (bytes memory) {
                                return functionCall(target, data, "Address: low-level call failed");
                              }
                              /**
                               * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`], but with
                               * `errorMessage` as a fallback revert reason when `target` reverts.
                               *
                               * _Available since v3.1._
                               */
                              function functionCall(address target, bytes memory data, string memory errorMessage) internal returns (bytes memory) {
                                  return functionCallWithValue(target, data, 0, errorMessage);
                              }
                              /**
                               * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
                               * but also transferring `value` wei to `target`.
                               *
                               * Requirements:
                               *
                               * - the calling contract must have an ETH balance of at least `value`.
                               * - the called Solidity function must be `payable`.
                               *
                               * _Available since v3.1._
                               */
                              function functionCallWithValue(address target, bytes memory data, uint256 value) internal returns (bytes memory) {
                                  return functionCallWithValue(target, data, value, "Address: low-level call with value failed");
                              }
                              /**
                               * @dev Same as {xref-Address-functionCallWithValue-address-bytes-uint256-}[`functionCallWithValue`], but
                               * with `errorMessage` as a fallback revert reason when `target` reverts.
                               *
                               * _Available since v3.1._
                               */
                              function functionCallWithValue(address target, bytes memory data, uint256 value, string memory errorMessage) internal returns (bytes memory) {
                                  require(address(this).balance >= value, "Address: insufficient balance for call");
                                  require(isContract(target), "Address: call to non-contract");
                                  // solhint-disable-next-line avoid-low-level-calls
                                  (bool success, bytes memory returndata) = target.call{ value: value }(data);
                                  return _verifyCallResult(success, returndata, errorMessage);
                              }
                              /**
                               * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
                               * but performing a static call.
                               *
                               * _Available since v3.3._
                               */
                              function functionStaticCall(address target, bytes memory data) internal view returns (bytes memory) {
                                  return functionStaticCall(target, data, "Address: low-level static call failed");
                              }
                              /**
                               * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
                               * but performing a static call.
                               *
                               * _Available since v3.3._
                               */
                              function functionStaticCall(address target, bytes memory data, string memory errorMessage) internal view returns (bytes memory) {
                                  require(isContract(target), "Address: static call to non-contract");
                                  // solhint-disable-next-line avoid-low-level-calls
                                  (bool success, bytes memory returndata) = target.staticcall(data);
                                  return _verifyCallResult(success, returndata, errorMessage);
                              }
                              /**
                               * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
                               * but performing a delegate call.
                               *
                               * _Available since v3.4._
                               */
                              function functionDelegateCall(address target, bytes memory data) internal returns (bytes memory) {
                                  return functionDelegateCall(target, data, "Address: low-level delegate call failed");
                              }
                              /**
                               * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
                               * but performing a delegate call.
                               *
                               * _Available since v3.4._
                               */
                              function functionDelegateCall(address target, bytes memory data, string memory errorMessage) internal returns (bytes memory) {
                                  require(isContract(target), "Address: delegate call to non-contract");
                                  // solhint-disable-next-line avoid-low-level-calls
                                  (bool success, bytes memory returndata) = target.delegatecall(data);
                                  return _verifyCallResult(success, returndata, errorMessage);
                              }
                              function _verifyCallResult(bool success, bytes memory returndata, string memory errorMessage) private pure returns(bytes memory) {
                                  if (success) {
                                      return returndata;
                                  } else {
                                      // Look for revert reason and bubble it up if present
                                      if (returndata.length > 0) {
                                          // The easiest way to bubble the revert reason is using memory via assembly
                                          // solhint-disable-next-line no-inline-assembly
                                          assembly {
                                              let returndata_size := mload(returndata)
                                              revert(add(32, returndata), returndata_size)
                                          }
                                      } else {
                                          revert(errorMessage);
                                      }
                                  }
                              }
                          }
                          // SPDX-License-Identifier: MIT
                          pragma solidity >=0.6.0 <0.8.0;
                          import "./IERC20.sol";
                          import "../../math/SafeMath.sol";
                          import "../../utils/Address.sol";
                          /**
                           * @title SafeERC20
                           * @dev Wrappers around ERC20 operations that throw on failure (when the token
                           * contract returns false). Tokens that return no value (and instead revert or
                           * throw on failure) are also supported, non-reverting calls are assumed to be
                           * successful.
                           * To use this library you can add a `using SafeERC20 for IERC20;` statement to your contract,
                           * which allows you to call the safe operations as `token.safeTransfer(...)`, etc.
                           */
                          library SafeERC20 {
                              using SafeMath for uint256;
                              using Address for address;
                              function safeTransfer(IERC20 token, address to, uint256 value) internal {
                                  _callOptionalReturn(token, abi.encodeWithSelector(token.transfer.selector, to, value));
                              }
                              function safeTransferFrom(IERC20 token, address from, address to, uint256 value) internal {
                                  _callOptionalReturn(token, abi.encodeWithSelector(token.transferFrom.selector, from, to, value));
                              }
                              /**
                               * @dev Deprecated. This function has issues similar to the ones found in
                               * {IERC20-approve}, and its usage is discouraged.
                               *
                               * Whenever possible, use {safeIncreaseAllowance} and
                               * {safeDecreaseAllowance} instead.
                               */
                              function safeApprove(IERC20 token, address spender, uint256 value) internal {
                                  // safeApprove should only be called when setting an initial allowance,
                                  // or when resetting it to zero. To increase and decrease it, use
                                  // 'safeIncreaseAllowance' and 'safeDecreaseAllowance'
                                  // solhint-disable-next-line max-line-length
                                  require((value == 0) || (token.allowance(address(this), spender) == 0),
                                      "SafeERC20: approve from non-zero to non-zero allowance"
                                  );
                                  _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, value));
                              }
                              function safeIncreaseAllowance(IERC20 token, address spender, uint256 value) internal {
                                  uint256 newAllowance = token.allowance(address(this), spender).add(value);
                                  _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, newAllowance));
                              }
                              function safeDecreaseAllowance(IERC20 token, address spender, uint256 value) internal {
                                  uint256 newAllowance = token.allowance(address(this), spender).sub(value, "SafeERC20: decreased allowance below zero");
                                  _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, newAllowance));
                              }
                              /**
                               * @dev Imitates a Solidity high-level call (i.e. a regular function call to a contract), relaxing the requirement
                               * on the return value: the return value is optional (but if data is returned, it must not be false).
                               * @param token The token targeted by the call.
                               * @param data The call data (encoded using abi.encode or one of its variants).
                               */
                              function _callOptionalReturn(IERC20 token, bytes memory data) private {
                                  // We need to perform a low level call here, to bypass Solidity's return data size checking mechanism, since
                                  // we're implementing it ourselves. We use {Address.functionCall} to perform this call, which verifies that
                                  // the target address contains contract code and also asserts for success in the low-level call.
                                  bytes memory returndata = address(token).functionCall(data, "SafeERC20: low-level call failed");
                                  if (returndata.length > 0) { // Return data is optional
                                      // solhint-disable-next-line max-line-length
                                      require(abi.decode(returndata, (bool)), "SafeERC20: ERC20 operation did not succeed");
                                  }
                              }
                          }
                          // SPDX-License-Identifier: MIT
                          pragma solidity >=0.6.0 <0.8.0;
                          /**
                           * @dev Interface of the ERC20 standard as defined in the EIP.
                           */
                          interface IERC20 {
                              /**
                               * @dev Returns the amount of tokens in existence.
                               */
                              function totalSupply() external view returns (uint256);
                              /**
                               * @dev Returns the amount of tokens owned by `account`.
                               */
                              function balanceOf(address account) external view returns (uint256);
                              /**
                               * @dev Moves `amount` tokens from the caller's account to `recipient`.
                               *
                               * Returns a boolean value indicating whether the operation succeeded.
                               *
                               * Emits a {Transfer} event.
                               */
                              function transfer(address recipient, uint256 amount) external returns (bool);
                              /**
                               * @dev Returns the remaining number of tokens that `spender` will be
                               * allowed to spend on behalf of `owner` through {transferFrom}. This is
                               * zero by default.
                               *
                               * This value changes when {approve} or {transferFrom} are called.
                               */
                              function allowance(address owner, address spender) external view returns (uint256);
                              /**
                               * @dev Sets `amount` as the allowance of `spender` over the caller's tokens.
                               *
                               * Returns a boolean value indicating whether the operation succeeded.
                               *
                               * IMPORTANT: Beware that changing an allowance with this method brings the risk
                               * that someone may use both the old and the new allowance by unfortunate
                               * transaction ordering. One possible solution to mitigate this race
                               * condition is to first reduce the spender's allowance to 0 and set the
                               * desired value afterwards:
                               * https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729
                               *
                               * Emits an {Approval} event.
                               */
                              function approve(address spender, uint256 amount) external returns (bool);
                              /**
                               * @dev Moves `amount` tokens from `sender` to `recipient` using the
                               * allowance mechanism. `amount` is then deducted from the caller's
                               * allowance.
                               *
                               * Returns a boolean value indicating whether the operation succeeded.
                               *
                               * Emits a {Transfer} event.
                               */
                              function transferFrom(address sender, address recipient, uint256 amount) external returns (bool);
                              /**
                               * @dev Emitted when `value` tokens are moved from one account (`from`) to
                               * another (`to`).
                               *
                               * Note that `value` may be zero.
                               */
                              event Transfer(address indexed from, address indexed to, uint256 value);
                              /**
                               * @dev Emitted when the allowance of a `spender` for an `owner` is set by
                               * a call to {approve}. `value` is the new allowance.
                               */
                              event Approval(address indexed owner, address indexed spender, uint256 value);
                          }
                          // SPDX-License-Identifier: MIT
                          pragma solidity >=0.6.0 <0.8.0;
                          /**
                           * @dev Wrappers over Solidity's arithmetic operations with added overflow
                           * checks.
                           *
                           * Arithmetic operations in Solidity wrap on overflow. This can easily result
                           * in bugs, because programmers usually assume that an overflow raises an
                           * error, which is the standard behavior in high level programming languages.
                           * `SafeMath` restores this intuition by reverting the transaction when an
                           * operation overflows.
                           *
                           * Using this library instead of the unchecked operations eliminates an entire
                           * class of bugs, so it's recommended to use it always.
                           */
                          library SafeMath {
                              /**
                               * @dev Returns the addition of two unsigned integers, with an overflow flag.
                               *
                               * _Available since v3.4._
                               */
                              function tryAdd(uint256 a, uint256 b) internal pure returns (bool, uint256) {
                                  uint256 c = a + b;
                                  if (c < a) return (false, 0);
                                  return (true, c);
                              }
                              /**
                               * @dev Returns the substraction of two unsigned integers, with an overflow flag.
                               *
                               * _Available since v3.4._
                               */
                              function trySub(uint256 a, uint256 b) internal pure returns (bool, uint256) {
                                  if (b > a) return (false, 0);
                                  return (true, a - b);
                              }
                              /**
                               * @dev Returns the multiplication of two unsigned integers, with an overflow flag.
                               *
                               * _Available since v3.4._
                               */
                              function tryMul(uint256 a, uint256 b) internal pure returns (bool, uint256) {
                                  // Gas optimization: this is cheaper than requiring 'a' not being zero, but the
                                  // benefit is lost if 'b' is also tested.
                                  // See: https://github.com/OpenZeppelin/openzeppelin-contracts/pull/522
                                  if (a == 0) return (true, 0);
                                  uint256 c = a * b;
                                  if (c / a != b) return (false, 0);
                                  return (true, c);
                              }
                              /**
                               * @dev Returns the division of two unsigned integers, with a division by zero flag.
                               *
                               * _Available since v3.4._
                               */
                              function tryDiv(uint256 a, uint256 b) internal pure returns (bool, uint256) {
                                  if (b == 0) return (false, 0);
                                  return (true, a / b);
                              }
                              /**
                               * @dev Returns the remainder of dividing two unsigned integers, with a division by zero flag.
                               *
                               * _Available since v3.4._
                               */
                              function tryMod(uint256 a, uint256 b) internal pure returns (bool, uint256) {
                                  if (b == 0) return (false, 0);
                                  return (true, a % b);
                              }
                              /**
                               * @dev Returns the addition of two unsigned integers, reverting on
                               * overflow.
                               *
                               * Counterpart to Solidity's `+` operator.
                               *
                               * Requirements:
                               *
                               * - Addition cannot overflow.
                               */
                              function add(uint256 a, uint256 b) internal pure returns (uint256) {
                                  uint256 c = a + b;
                                  require(c >= a, "SafeMath: addition overflow");
                                  return c;
                              }
                              /**
                               * @dev Returns the subtraction of two unsigned integers, reverting on
                               * overflow (when the result is negative).
                               *
                               * Counterpart to Solidity's `-` operator.
                               *
                               * Requirements:
                               *
                               * - Subtraction cannot overflow.
                               */
                              function sub(uint256 a, uint256 b) internal pure returns (uint256) {
                                  require(b <= a, "SafeMath: subtraction overflow");
                                  return a - b;
                              }
                              /**
                               * @dev Returns the multiplication of two unsigned integers, reverting on
                               * overflow.
                               *
                               * Counterpart to Solidity's `*` operator.
                               *
                               * Requirements:
                               *
                               * - Multiplication cannot overflow.
                               */
                              function mul(uint256 a, uint256 b) internal pure returns (uint256) {
                                  if (a == 0) return 0;
                                  uint256 c = a * b;
                                  require(c / a == b, "SafeMath: multiplication overflow");
                                  return c;
                              }
                              /**
                               * @dev Returns the integer division of two unsigned integers, reverting on
                               * division by zero. The result is rounded towards zero.
                               *
                               * Counterpart to Solidity's `/` operator. Note: this function uses a
                               * `revert` opcode (which leaves remaining gas untouched) while Solidity
                               * uses an invalid opcode to revert (consuming all remaining gas).
                               *
                               * Requirements:
                               *
                               * - The divisor cannot be zero.
                               */
                              function div(uint256 a, uint256 b) internal pure returns (uint256) {
                                  require(b > 0, "SafeMath: division by zero");
                                  return a / b;
                              }
                              /**
                               * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
                               * reverting when dividing by zero.
                               *
                               * Counterpart to Solidity's `%` operator. This function uses a `revert`
                               * opcode (which leaves remaining gas untouched) while Solidity uses an
                               * invalid opcode to revert (consuming all remaining gas).
                               *
                               * Requirements:
                               *
                               * - The divisor cannot be zero.
                               */
                              function mod(uint256 a, uint256 b) internal pure returns (uint256) {
                                  require(b > 0, "SafeMath: modulo by zero");
                                  return a % b;
                              }
                              /**
                               * @dev Returns the subtraction of two unsigned integers, reverting with custom message on
                               * overflow (when the result is negative).
                               *
                               * CAUTION: This function is deprecated because it requires allocating memory for the error
                               * message unnecessarily. For custom revert reasons use {trySub}.
                               *
                               * Counterpart to Solidity's `-` operator.
                               *
                               * Requirements:
                               *
                               * - Subtraction cannot overflow.
                               */
                              function sub(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
                                  require(b <= a, errorMessage);
                                  return a - b;
                              }
                              /**
                               * @dev Returns the integer division of two unsigned integers, reverting with custom message on
                               * division by zero. The result is rounded towards zero.
                               *
                               * CAUTION: This function is deprecated because it requires allocating memory for the error
                               * message unnecessarily. For custom revert reasons use {tryDiv}.
                               *
                               * Counterpart to Solidity's `/` operator. Note: this function uses a
                               * `revert` opcode (which leaves remaining gas untouched) while Solidity
                               * uses an invalid opcode to revert (consuming all remaining gas).
                               *
                               * Requirements:
                               *
                               * - The divisor cannot be zero.
                               */
                              function div(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
                                  require(b > 0, errorMessage);
                                  return a / b;
                              }
                              /**
                               * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
                               * reverting with custom message when dividing by zero.
                               *
                               * CAUTION: This function is deprecated because it requires allocating memory for the error
                               * message unnecessarily. For custom revert reasons use {tryMod}.
                               *
                               * Counterpart to Solidity's `%` operator. This function uses a `revert`
                               * opcode (which leaves remaining gas untouched) while Solidity uses an
                               * invalid opcode to revert (consuming all remaining gas).
                               *
                               * Requirements:
                               *
                               * - The divisor cannot be zero.
                               */
                              function mod(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
                                  require(b > 0, errorMessage);
                                  return a % b;
                              }
                          }
                          /**
                           * SPDX-License-Identifier: Apache-2.0
                           *
                           * Copyright (c) 2023, Circle Internet Financial, LLC.
                           *
                           * Licensed under the Apache License, Version 2.0 (the "License");
                           * you may not use this file except in compliance with the License.
                           * You may obtain a copy of the License at
                           *
                           * http://www.apache.org/licenses/LICENSE-2.0
                           *
                           * Unless required by applicable law or agreed to in writing, software
                           * distributed under the License is distributed on an "AS IS" BASIS,
                           * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
                           * See the License for the specific language governing permissions and
                           * limitations under the License.
                           */
                          pragma solidity 0.6.12;
                          import { FiatTokenV2 } from "./FiatTokenV2.sol";
                          // solhint-disable func-name-mixedcase
                          /**
                           * @title FiatToken V2.1
                           * @notice ERC20 Token backed by fiat reserves, version 2.1
                           */
                          contract FiatTokenV2_1 is FiatTokenV2 {
                              /**
                               * @notice Initialize v2.1
                               * @param lostAndFound  The address to which the locked funds are sent
                               */
                              function initializeV2_1(address lostAndFound) external {
                                  // solhint-disable-next-line reason-string
                                  require(_initializedVersion == 1);
                                  uint256 lockedAmount = _balanceOf(address(this));
                                  if (lockedAmount > 0) {
                                      _transfer(address(this), lostAndFound, lockedAmount);
                                  }
                                  _blacklist(address(this));
                                  _initializedVersion = 2;
                              }
                              /**
                               * @notice Version string for the EIP712 domain separator
                               * @return Version string
                               */
                              function version() external pure returns (string memory) {
                                  return "2";
                              }
                          }
                          /**
                           * SPDX-License-Identifier: Apache-2.0
                           *
                           * Copyright (c) 2023, Circle Internet Financial, LLC.
                           *
                           * Licensed under the Apache License, Version 2.0 (the "License");
                           * you may not use this file except in compliance with the License.
                           * You may obtain a copy of the License at
                           *
                           * http://www.apache.org/licenses/LICENSE-2.0
                           *
                           * Unless required by applicable law or agreed to in writing, software
                           * distributed under the License is distributed on an "AS IS" BASIS,
                           * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
                           * See the License for the specific language governing permissions and
                           * limitations under the License.
                           */
                          pragma solidity 0.6.12;
                          import { FiatTokenV1_1 } from "../v1.1/FiatTokenV1_1.sol";
                          import { EIP712 } from "../util/EIP712.sol";
                          import { EIP3009 } from "./EIP3009.sol";
                          import { EIP2612 } from "./EIP2612.sol";
                          /**
                           * @title FiatToken V2
                           * @notice ERC20 Token backed by fiat reserves, version 2
                           */
                          contract FiatTokenV2 is FiatTokenV1_1, EIP3009, EIP2612 {
                              uint8 internal _initializedVersion;
                              /**
                               * @notice Initialize v2
                               * @param newName   New token name
                               */
                              function initializeV2(string calldata newName) external {
                                  // solhint-disable-next-line reason-string
                                  require(initialized && _initializedVersion == 0);
                                  name = newName;
                                  _DEPRECATED_CACHED_DOMAIN_SEPARATOR = EIP712.makeDomainSeparator(
                                      newName,
                                      "2"
                                  );
                                  _initializedVersion = 1;
                              }
                              /**
                               * @notice Increase the allowance by a given increment
                               * @param spender   Spender's address
                               * @param increment Amount of increase in allowance
                               * @return True if successful
                               */
                              function increaseAllowance(address spender, uint256 increment)
                                  external
                                  virtual
                                  whenNotPaused
                                  notBlacklisted(msg.sender)
                                  notBlacklisted(spender)
                                  returns (bool)
                              {
                                  _increaseAllowance(msg.sender, spender, increment);
                                  return true;
                              }
                              /**
                               * @notice Decrease the allowance by a given decrement
                               * @param spender   Spender's address
                               * @param decrement Amount of decrease in allowance
                               * @return True if successful
                               */
                              function decreaseAllowance(address spender, uint256 decrement)
                                  external
                                  virtual
                                  whenNotPaused
                                  notBlacklisted(msg.sender)
                                  notBlacklisted(spender)
                                  returns (bool)
                              {
                                  _decreaseAllowance(msg.sender, spender, decrement);
                                  return true;
                              }
                              /**
                               * @notice Execute a transfer with a signed authorization
                               * @param from          Payer's address (Authorizer)
                               * @param to            Payee's address
                               * @param value         Amount to be transferred
                               * @param validAfter    The time after which this is valid (unix time)
                               * @param validBefore   The time before which this is valid (unix time)
                               * @param nonce         Unique nonce
                               * @param v             v of the signature
                               * @param r             r of the signature
                               * @param s             s of the signature
                               */
                              function transferWithAuthorization(
                                  address from,
                                  address to,
                                  uint256 value,
                                  uint256 validAfter,
                                  uint256 validBefore,
                                  bytes32 nonce,
                                  uint8 v,
                                  bytes32 r,
                                  bytes32 s
                              ) external whenNotPaused notBlacklisted(from) notBlacklisted(to) {
                                  _transferWithAuthorization(
                                      from,
                                      to,
                                      value,
                                      validAfter,
                                      validBefore,
                                      nonce,
                                      v,
                                      r,
                                      s
                                  );
                              }
                              /**
                               * @notice Receive a transfer with a signed authorization from the payer
                               * @dev This has an additional check to ensure that the payee's address
                               * matches the caller of this function to prevent front-running attacks.
                               * @param from          Payer's address (Authorizer)
                               * @param to            Payee's address
                               * @param value         Amount to be transferred
                               * @param validAfter    The time after which this is valid (unix time)
                               * @param validBefore   The time before which this is valid (unix time)
                               * @param nonce         Unique nonce
                               * @param v             v of the signature
                               * @param r             r of the signature
                               * @param s             s of the signature
                               */
                              function receiveWithAuthorization(
                                  address from,
                                  address to,
                                  uint256 value,
                                  uint256 validAfter,
                                  uint256 validBefore,
                                  bytes32 nonce,
                                  uint8 v,
                                  bytes32 r,
                                  bytes32 s
                              ) external whenNotPaused notBlacklisted(from) notBlacklisted(to) {
                                  _receiveWithAuthorization(
                                      from,
                                      to,
                                      value,
                                      validAfter,
                                      validBefore,
                                      nonce,
                                      v,
                                      r,
                                      s
                                  );
                              }
                              /**
                               * @notice Attempt to cancel an authorization
                               * @dev Works only if the authorization is not yet used.
                               * @param authorizer    Authorizer's address
                               * @param nonce         Nonce of the authorization
                               * @param v             v of the signature
                               * @param r             r of the signature
                               * @param s             s of the signature
                               */
                              function cancelAuthorization(
                                  address authorizer,
                                  bytes32 nonce,
                                  uint8 v,
                                  bytes32 r,
                                  bytes32 s
                              ) external whenNotPaused {
                                  _cancelAuthorization(authorizer, nonce, v, r, s);
                              }
                              /**
                               * @notice Update allowance with a signed permit
                               * @param owner       Token owner's address (Authorizer)
                               * @param spender     Spender's address
                               * @param value       Amount of allowance
                               * @param deadline    The time at which the signature expires (unix time), or max uint256 value to signal no expiration
                               * @param v           v of the signature
                               * @param r           r of the signature
                               * @param s           s of the signature
                               */
                              function permit(
                                  address owner,
                                  address spender,
                                  uint256 value,
                                  uint256 deadline,
                                  uint8 v,
                                  bytes32 r,
                                  bytes32 s
                              )
                                  external
                                  virtual
                                  whenNotPaused
                                  notBlacklisted(owner)
                                  notBlacklisted(spender)
                              {
                                  _permit(owner, spender, value, deadline, v, r, s);
                              }
                              /**
                               * @dev Internal function to increase the allowance by a given increment
                               * @param owner     Token owner's address
                               * @param spender   Spender's address
                               * @param increment Amount of increase
                               */
                              function _increaseAllowance(
                                  address owner,
                                  address spender,
                                  uint256 increment
                              ) internal override {
                                  _approve(owner, spender, allowed[owner][spender].add(increment));
                              }
                              /**
                               * @dev Internal function to decrease the allowance by a given decrement
                               * @param owner     Token owner's address
                               * @param spender   Spender's address
                               * @param decrement Amount of decrease
                               */
                              function _decreaseAllowance(
                                  address owner,
                                  address spender,
                                  uint256 decrement
                              ) internal override {
                                  _approve(
                                      owner,
                                      spender,
                                      allowed[owner][spender].sub(
                                          decrement,
                                          "ERC20: decreased allowance below zero"
                                      )
                                  );
                              }
                          }
                          /**
                           * SPDX-License-Identifier: Apache-2.0
                           *
                           * Copyright (c) 2023, Circle Internet Financial, LLC.
                           *
                           * Licensed under the Apache License, Version 2.0 (the "License");
                           * you may not use this file except in compliance with the License.
                           * You may obtain a copy of the License at
                           *
                           * http://www.apache.org/licenses/LICENSE-2.0
                           *
                           * Unless required by applicable law or agreed to in writing, software
                           * distributed under the License is distributed on an "AS IS" BASIS,
                           * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
                           * See the License for the specific language governing permissions and
                           * limitations under the License.
                           */
                          pragma solidity 0.6.12;
                          // solhint-disable func-name-mixedcase
                          /**
                           * @title EIP712 Domain
                           */
                          contract EIP712Domain {
                              // was originally DOMAIN_SEPARATOR
                              // but that has been moved to a method so we can override it in V2_2+
                              bytes32 internal _DEPRECATED_CACHED_DOMAIN_SEPARATOR;
                              /**
                               * @notice Get the EIP712 Domain Separator.
                               * @return The bytes32 EIP712 domain separator.
                               */
                              function DOMAIN_SEPARATOR() external view returns (bytes32) {
                                  return _domainSeparator();
                              }
                              /**
                               * @dev Internal method to get the EIP712 Domain Separator.
                               * @return The bytes32 EIP712 domain separator.
                               */
                              function _domainSeparator() internal virtual view returns (bytes32) {
                                  return _DEPRECATED_CACHED_DOMAIN_SEPARATOR;
                              }
                          }
                          /**
                           * SPDX-License-Identifier: Apache-2.0
                           *
                           * Copyright (c) 2023, Circle Internet Financial, LLC.
                           *
                           * Licensed under the Apache License, Version 2.0 (the "License");
                           * you may not use this file except in compliance with the License.
                           * You may obtain a copy of the License at
                           *
                           * http://www.apache.org/licenses/LICENSE-2.0
                           *
                           * Unless required by applicable law or agreed to in writing, software
                           * distributed under the License is distributed on an "AS IS" BASIS,
                           * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
                           * See the License for the specific language governing permissions and
                           * limitations under the License.
                           */
                          pragma solidity 0.6.12;
                          import { AbstractFiatTokenV2 } from "./AbstractFiatTokenV2.sol";
                          import { EIP712Domain } from "./EIP712Domain.sol";
                          import { SignatureChecker } from "../util/SignatureChecker.sol";
                          import { MessageHashUtils } from "../util/MessageHashUtils.sol";
                          /**
                           * @title EIP-3009
                           * @notice Provide internal implementation for gas-abstracted transfers
                           * @dev Contracts that inherit from this must wrap these with publicly
                           * accessible functions, optionally adding modifiers where necessary
                           */
                          abstract contract EIP3009 is AbstractFiatTokenV2, EIP712Domain {
                              // keccak256("TransferWithAuthorization(address from,address to,uint256 value,uint256 validAfter,uint256 validBefore,bytes32 nonce)")
                              bytes32
                                  public constant TRANSFER_WITH_AUTHORIZATION_TYPEHASH = 0x7c7c6cdb67a18743f49ec6fa9b35f50d52ed05cbed4cc592e13b44501c1a2267;
                              // keccak256("ReceiveWithAuthorization(address from,address to,uint256 value,uint256 validAfter,uint256 validBefore,bytes32 nonce)")
                              bytes32
                                  public constant RECEIVE_WITH_AUTHORIZATION_TYPEHASH = 0xd099cc98ef71107a616c4f0f941f04c322d8e254fe26b3c6668db87aae413de8;
                              // keccak256("CancelAuthorization(address authorizer,bytes32 nonce)")
                              bytes32
                                  public constant CANCEL_AUTHORIZATION_TYPEHASH = 0x158b0a9edf7a828aad02f63cd515c68ef2f50ba807396f6d12842833a1597429;
                              /**
                               * @dev authorizer address => nonce => bool (true if nonce is used)
                               */
                              mapping(address => mapping(bytes32 => bool)) private _authorizationStates;
                              event AuthorizationUsed(address indexed authorizer, bytes32 indexed nonce);
                              event AuthorizationCanceled(
                                  address indexed authorizer,
                                  bytes32 indexed nonce
                              );
                              /**
                               * @notice Returns the state of an authorization
                               * @dev Nonces are randomly generated 32-byte data unique to the
                               * authorizer's address
                               * @param authorizer    Authorizer's address
                               * @param nonce         Nonce of the authorization
                               * @return True if the nonce is used
                               */
                              function authorizationState(address authorizer, bytes32 nonce)
                                  external
                                  view
                                  returns (bool)
                              {
                                  return _authorizationStates[authorizer][nonce];
                              }
                              /**
                               * @notice Execute a transfer with a signed authorization
                               * @param from          Payer's address (Authorizer)
                               * @param to            Payee's address
                               * @param value         Amount to be transferred
                               * @param validAfter    The time after which this is valid (unix time)
                               * @param validBefore   The time before which this is valid (unix time)
                               * @param nonce         Unique nonce
                               * @param v             v of the signature
                               * @param r             r of the signature
                               * @param s             s of the signature
                               */
                              function _transferWithAuthorization(
                                  address from,
                                  address to,
                                  uint256 value,
                                  uint256 validAfter,
                                  uint256 validBefore,
                                  bytes32 nonce,
                                  uint8 v,
                                  bytes32 r,
                                  bytes32 s
                              ) internal {
                                  _transferWithAuthorization(
                                      from,
                                      to,
                                      value,
                                      validAfter,
                                      validBefore,
                                      nonce,
                                      abi.encodePacked(r, s, v)
                                  );
                              }
                              /**
                               * @notice Execute a transfer with a signed authorization
                               * @dev EOA wallet signatures should be packed in the order of r, s, v.
                               * @param from          Payer's address (Authorizer)
                               * @param to            Payee's address
                               * @param value         Amount to be transferred
                               * @param validAfter    The time after which this is valid (unix time)
                               * @param validBefore   The time before which this is valid (unix time)
                               * @param nonce         Unique nonce
                               * @param signature     Signature byte array produced by an EOA wallet or a contract wallet
                               */
                              function _transferWithAuthorization(
                                  address from,
                                  address to,
                                  uint256 value,
                                  uint256 validAfter,
                                  uint256 validBefore,
                                  bytes32 nonce,
                                  bytes memory signature
                              ) internal {
                                  _requireValidAuthorization(from, nonce, validAfter, validBefore);
                                  _requireValidSignature(
                                      from,
                                      keccak256(
                                          abi.encode(
                                              TRANSFER_WITH_AUTHORIZATION_TYPEHASH,
                                              from,
                                              to,
                                              value,
                                              validAfter,
                                              validBefore,
                                              nonce
                                          )
                                      ),
                                      signature
                                  );
                                  _markAuthorizationAsUsed(from, nonce);
                                  _transfer(from, to, value);
                              }
                              /**
                               * @notice Receive a transfer with a signed authorization from the payer
                               * @dev This has an additional check to ensure that the payee's address
                               * matches the caller of this function to prevent front-running attacks.
                               * @param from          Payer's address (Authorizer)
                               * @param to            Payee's address
                               * @param value         Amount to be transferred
                               * @param validAfter    The time after which this is valid (unix time)
                               * @param validBefore   The time before which this is valid (unix time)
                               * @param nonce         Unique nonce
                               * @param v             v of the signature
                               * @param r             r of the signature
                               * @param s             s of the signature
                               */
                              function _receiveWithAuthorization(
                                  address from,
                                  address to,
                                  uint256 value,
                                  uint256 validAfter,
                                  uint256 validBefore,
                                  bytes32 nonce,
                                  uint8 v,
                                  bytes32 r,
                                  bytes32 s
                              ) internal {
                                  _receiveWithAuthorization(
                                      from,
                                      to,
                                      value,
                                      validAfter,
                                      validBefore,
                                      nonce,
                                      abi.encodePacked(r, s, v)
                                  );
                              }
                              /**
                               * @notice Receive a transfer with a signed authorization from the payer
                               * @dev This has an additional check to ensure that the payee's address
                               * matches the caller of this function to prevent front-running attacks.
                               * EOA wallet signatures should be packed in the order of r, s, v.
                               * @param from          Payer's address (Authorizer)
                               * @param to            Payee's address
                               * @param value         Amount to be transferred
                               * @param validAfter    The time after which this is valid (unix time)
                               * @param validBefore   The time before which this is valid (unix time)
                               * @param nonce         Unique nonce
                               * @param signature     Signature byte array produced by an EOA wallet or a contract wallet
                               */
                              function _receiveWithAuthorization(
                                  address from,
                                  address to,
                                  uint256 value,
                                  uint256 validAfter,
                                  uint256 validBefore,
                                  bytes32 nonce,
                                  bytes memory signature
                              ) internal {
                                  require(to == msg.sender, "FiatTokenV2: caller must be the payee");
                                  _requireValidAuthorization(from, nonce, validAfter, validBefore);
                                  _requireValidSignature(
                                      from,
                                      keccak256(
                                          abi.encode(
                                              RECEIVE_WITH_AUTHORIZATION_TYPEHASH,
                                              from,
                                              to,
                                              value,
                                              validAfter,
                                              validBefore,
                                              nonce
                                          )
                                      ),
                                      signature
                                  );
                                  _markAuthorizationAsUsed(from, nonce);
                                  _transfer(from, to, value);
                              }
                              /**
                               * @notice Attempt to cancel an authorization
                               * @param authorizer    Authorizer's address
                               * @param nonce         Nonce of the authorization
                               * @param v             v of the signature
                               * @param r             r of the signature
                               * @param s             s of the signature
                               */
                              function _cancelAuthorization(
                                  address authorizer,
                                  bytes32 nonce,
                                  uint8 v,
                                  bytes32 r,
                                  bytes32 s
                              ) internal {
                                  _cancelAuthorization(authorizer, nonce, abi.encodePacked(r, s, v));
                              }
                              /**
                               * @notice Attempt to cancel an authorization
                               * @dev EOA wallet signatures should be packed in the order of r, s, v.
                               * @param authorizer    Authorizer's address
                               * @param nonce         Nonce of the authorization
                               * @param signature     Signature byte array produced by an EOA wallet or a contract wallet
                               */
                              function _cancelAuthorization(
                                  address authorizer,
                                  bytes32 nonce,
                                  bytes memory signature
                              ) internal {
                                  _requireUnusedAuthorization(authorizer, nonce);
                                  _requireValidSignature(
                                      authorizer,
                                      keccak256(
                                          abi.encode(CANCEL_AUTHORIZATION_TYPEHASH, authorizer, nonce)
                                      ),
                                      signature
                                  );
                                  _authorizationStates[authorizer][nonce] = true;
                                  emit AuthorizationCanceled(authorizer, nonce);
                              }
                              /**
                               * @notice Validates that signature against input data struct
                               * @param signer        Signer's address
                               * @param dataHash      Hash of encoded data struct
                               * @param signature     Signature byte array produced by an EOA wallet or a contract wallet
                               */
                              function _requireValidSignature(
                                  address signer,
                                  bytes32 dataHash,
                                  bytes memory signature
                              ) private view {
                                  require(
                                      SignatureChecker.isValidSignatureNow(
                                          signer,
                                          MessageHashUtils.toTypedDataHash(_domainSeparator(), dataHash),
                                          signature
                                      ),
                                      "FiatTokenV2: invalid signature"
                                  );
                              }
                              /**
                               * @notice Check that an authorization is unused
                               * @param authorizer    Authorizer's address
                               * @param nonce         Nonce of the authorization
                               */
                              function _requireUnusedAuthorization(address authorizer, bytes32 nonce)
                                  private
                                  view
                              {
                                  require(
                                      !_authorizationStates[authorizer][nonce],
                                      "FiatTokenV2: authorization is used or canceled"
                                  );
                              }
                              /**
                               * @notice Check that authorization is valid
                               * @param authorizer    Authorizer's address
                               * @param nonce         Nonce of the authorization
                               * @param validAfter    The time after which this is valid (unix time)
                               * @param validBefore   The time before which this is valid (unix time)
                               */
                              function _requireValidAuthorization(
                                  address authorizer,
                                  bytes32 nonce,
                                  uint256 validAfter,
                                  uint256 validBefore
                              ) private view {
                                  require(
                                      now > validAfter,
                                      "FiatTokenV2: authorization is not yet valid"
                                  );
                                  require(now < validBefore, "FiatTokenV2: authorization is expired");
                                  _requireUnusedAuthorization(authorizer, nonce);
                              }
                              /**
                               * @notice Mark an authorization as used
                               * @param authorizer    Authorizer's address
                               * @param nonce         Nonce of the authorization
                               */
                              function _markAuthorizationAsUsed(address authorizer, bytes32 nonce)
                                  private
                              {
                                  _authorizationStates[authorizer][nonce] = true;
                                  emit AuthorizationUsed(authorizer, nonce);
                              }
                          }
                          /**
                           * SPDX-License-Identifier: Apache-2.0
                           *
                           * Copyright (c) 2023, Circle Internet Financial, LLC.
                           *
                           * Licensed under the Apache License, Version 2.0 (the "License");
                           * you may not use this file except in compliance with the License.
                           * You may obtain a copy of the License at
                           *
                           * http://www.apache.org/licenses/LICENSE-2.0
                           *
                           * Unless required by applicable law or agreed to in writing, software
                           * distributed under the License is distributed on an "AS IS" BASIS,
                           * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
                           * See the License for the specific language governing permissions and
                           * limitations under the License.
                           */
                          pragma solidity 0.6.12;
                          import { AbstractFiatTokenV2 } from "./AbstractFiatTokenV2.sol";
                          import { EIP712Domain } from "./EIP712Domain.sol";
                          import { MessageHashUtils } from "../util/MessageHashUtils.sol";
                          import { SignatureChecker } from "../util/SignatureChecker.sol";
                          /**
                           * @title EIP-2612
                           * @notice Provide internal implementation for gas-abstracted approvals
                           */
                          abstract contract EIP2612 is AbstractFiatTokenV2, EIP712Domain {
                              // keccak256("Permit(address owner,address spender,uint256 value,uint256 nonce,uint256 deadline)")
                              bytes32
                                  public constant PERMIT_TYPEHASH = 0x6e71edae12b1b97f4d1f60370fef10105fa2faae0126114a169c64845d6126c9;
                              mapping(address => uint256) private _permitNonces;
                              /**
                               * @notice Nonces for permit
                               * @param owner Token owner's address (Authorizer)
                               * @return Next nonce
                               */
                              function nonces(address owner) external view returns (uint256) {
                                  return _permitNonces[owner];
                              }
                              /**
                               * @notice Verify a signed approval permit and execute if valid
                               * @param owner     Token owner's address (Authorizer)
                               * @param spender   Spender's address
                               * @param value     Amount of allowance
                               * @param deadline  The time at which the signature expires (unix time), or max uint256 value to signal no expiration
                               * @param v         v of the signature
                               * @param r         r of the signature
                               * @param s         s of the signature
                               */
                              function _permit(
                                  address owner,
                                  address spender,
                                  uint256 value,
                                  uint256 deadline,
                                  uint8 v,
                                  bytes32 r,
                                  bytes32 s
                              ) internal {
                                  _permit(owner, spender, value, deadline, abi.encodePacked(r, s, v));
                              }
                              /**
                               * @notice Verify a signed approval permit and execute if valid
                               * @dev EOA wallet signatures should be packed in the order of r, s, v.
                               * @param owner      Token owner's address (Authorizer)
                               * @param spender    Spender's address
                               * @param value      Amount of allowance
                               * @param deadline   The time at which the signature expires (unix time), or max uint256 value to signal no expiration
                               * @param signature  Signature byte array signed by an EOA wallet or a contract wallet
                               */
                              function _permit(
                                  address owner,
                                  address spender,
                                  uint256 value,
                                  uint256 deadline,
                                  bytes memory signature
                              ) internal {
                                  require(
                                      deadline == type(uint256).max || deadline >= now,
                                      "FiatTokenV2: permit is expired"
                                  );
                                  bytes32 typedDataHash = MessageHashUtils.toTypedDataHash(
                                      _domainSeparator(),
                                      keccak256(
                                          abi.encode(
                                              PERMIT_TYPEHASH,
                                              owner,
                                              spender,
                                              value,
                                              _permitNonces[owner]++,
                                              deadline
                                          )
                                      )
                                  );
                                  require(
                                      SignatureChecker.isValidSignatureNow(
                                          owner,
                                          typedDataHash,
                                          signature
                                      ),
                                      "EIP2612: invalid signature"
                                  );
                                  _approve(owner, spender, value);
                              }
                          }
                          /**
                           * SPDX-License-Identifier: Apache-2.0
                           *
                           * Copyright (c) 2023, Circle Internet Financial, LLC.
                           *
                           * Licensed under the Apache License, Version 2.0 (the "License");
                           * you may not use this file except in compliance with the License.
                           * You may obtain a copy of the License at
                           *
                           * http://www.apache.org/licenses/LICENSE-2.0
                           *
                           * Unless required by applicable law or agreed to in writing, software
                           * distributed under the License is distributed on an "AS IS" BASIS,
                           * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
                           * See the License for the specific language governing permissions and
                           * limitations under the License.
                           */
                          pragma solidity 0.6.12;
                          import { AbstractFiatTokenV1 } from "../v1/AbstractFiatTokenV1.sol";
                          abstract contract AbstractFiatTokenV2 is AbstractFiatTokenV1 {
                              function _increaseAllowance(
                                  address owner,
                                  address spender,
                                  uint256 increment
                              ) internal virtual;
                              function _decreaseAllowance(
                                  address owner,
                                  address spender,
                                  uint256 decrement
                              ) internal virtual;
                          }
                          /**
                           * SPDX-License-Identifier: MIT
                           *
                           * Copyright (c) 2016 Smart Contract Solutions, Inc.
                           * Copyright (c) 2018-2020 CENTRE SECZ
                           *
                           * Permission is hereby granted, free of charge, to any person obtaining a copy
                           * of this software and associated documentation files (the "Software"), to deal
                           * in the Software without restriction, including without limitation the rights
                           * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
                           * copies of the Software, and to permit persons to whom the Software is
                           * furnished to do so, subject to the following conditions:
                           *
                           * The above copyright notice and this permission notice shall be included in
                           * copies or substantial portions of the Software.
                           *
                           * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
                           * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
                           * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
                           * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
                           * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
                           * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
                           * SOFTWARE.
                           */
                          pragma solidity 0.6.12;
                          import { Ownable } from "./Ownable.sol";
                          /**
                           * @notice Base contract which allows children to implement an emergency stop
                           * mechanism
                           * @dev Forked from https://github.com/OpenZeppelin/openzeppelin-contracts/blob/feb665136c0dae9912e08397c1a21c4af3651ef3/contracts/lifecycle/Pausable.sol
                           * Modifications:
                           * 1. Added pauser role, switched pause/unpause to be onlyPauser (6/14/2018)
                           * 2. Removed whenNotPause/whenPaused from pause/unpause (6/14/2018)
                           * 3. Removed whenPaused (6/14/2018)
                           * 4. Switches ownable library to use ZeppelinOS (7/12/18)
                           * 5. Remove constructor (7/13/18)
                           * 6. Reformat, conform to Solidity 0.6 syntax and add error messages (5/13/20)
                           * 7. Make public functions external (5/27/20)
                           */
                          contract Pausable is Ownable {
                              event Pause();
                              event Unpause();
                              event PauserChanged(address indexed newAddress);
                              address public pauser;
                              bool public paused = false;
                              /**
                               * @dev Modifier to make a function callable only when the contract is not paused.
                               */
                              modifier whenNotPaused() {
                                  require(!paused, "Pausable: paused");
                                  _;
                              }
                              /**
                               * @dev throws if called by any account other than the pauser
                               */
                              modifier onlyPauser() {
                                  require(msg.sender == pauser, "Pausable: caller is not the pauser");
                                  _;
                              }
                              /**
                               * @dev called by the owner to pause, triggers stopped state
                               */
                              function pause() external onlyPauser {
                                  paused = true;
                                  emit Pause();
                              }
                              /**
                               * @dev called by the owner to unpause, returns to normal state
                               */
                              function unpause() external onlyPauser {
                                  paused = false;
                                  emit Unpause();
                              }
                              /**
                               * @notice Updates the pauser address.
                               * @param _newPauser The address of the new pauser.
                               */
                              function updatePauser(address _newPauser) external onlyOwner {
                                  require(
                                      _newPauser != address(0),
                                      "Pausable: new pauser is the zero address"
                                  );
                                  pauser = _newPauser;
                                  emit PauserChanged(pauser);
                              }
                          }
                          /**
                           * SPDX-License-Identifier: MIT
                           *
                           * Copyright (c) 2018 zOS Global Limited.
                           * Copyright (c) 2018-2020 CENTRE SECZ
                           *
                           * Permission is hereby granted, free of charge, to any person obtaining a copy
                           * of this software and associated documentation files (the "Software"), to deal
                           * in the Software without restriction, including without limitation the rights
                           * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
                           * copies of the Software, and to permit persons to whom the Software is
                           * furnished to do so, subject to the following conditions:
                           *
                           * The above copyright notice and this permission notice shall be included in
                           * copies or substantial portions of the Software.
                           *
                           * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
                           * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
                           * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
                           * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
                           * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
                           * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
                           * SOFTWARE.
                           */
                          pragma solidity 0.6.12;
                          /**
                           * @notice The Ownable contract has an owner address, and provides basic
                           * authorization control functions
                           * @dev Forked from https://github.com/OpenZeppelin/openzeppelin-labs/blob/3887ab77b8adafba4a26ace002f3a684c1a3388b/upgradeability_ownership/contracts/ownership/Ownable.sol
                           * Modifications:
                           * 1. Consolidate OwnableStorage into this contract (7/13/18)
                           * 2. Reformat, conform to Solidity 0.6 syntax, and add error messages (5/13/20)
                           * 3. Make public functions external (5/27/20)
                           */
                          contract Ownable {
                              // Owner of the contract
                              address private _owner;
                              /**
                               * @dev Event to show ownership has been transferred
                               * @param previousOwner representing the address of the previous owner
                               * @param newOwner representing the address of the new owner
                               */
                              event OwnershipTransferred(address previousOwner, address newOwner);
                              /**
                               * @dev The constructor sets the original owner of the contract to the sender account.
                               */
                              constructor() public {
                                  setOwner(msg.sender);
                              }
                              /**
                               * @dev Tells the address of the owner
                               * @return the address of the owner
                               */
                              function owner() external view returns (address) {
                                  return _owner;
                              }
                              /**
                               * @dev Sets a new owner address
                               */
                              function setOwner(address newOwner) internal {
                                  _owner = newOwner;
                              }
                              /**
                               * @dev Throws if called by any account other than the owner.
                               */
                              modifier onlyOwner() {
                                  require(msg.sender == _owner, "Ownable: caller is not the owner");
                                  _;
                              }
                              /**
                               * @dev Allows the current owner to transfer control of the contract to a newOwner.
                               * @param newOwner The address to transfer ownership to.
                               */
                              function transferOwnership(address newOwner) external onlyOwner {
                                  require(
                                      newOwner != address(0),
                                      "Ownable: new owner is the zero address"
                                  );
                                  emit OwnershipTransferred(_owner, newOwner);
                                  setOwner(newOwner);
                              }
                          }
                          /**
                           * SPDX-License-Identifier: Apache-2.0
                           *
                           * Copyright (c) 2023, Circle Internet Financial, LLC.
                           *
                           * Licensed under the Apache License, Version 2.0 (the "License");
                           * you may not use this file except in compliance with the License.
                           * You may obtain a copy of the License at
                           *
                           * http://www.apache.org/licenses/LICENSE-2.0
                           *
                           * Unless required by applicable law or agreed to in writing, software
                           * distributed under the License is distributed on an "AS IS" BASIS,
                           * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
                           * See the License for the specific language governing permissions and
                           * limitations under the License.
                           */
                          pragma solidity 0.6.12;
                          import { SafeMath } from "@openzeppelin/contracts/math/SafeMath.sol";
                          import { AbstractFiatTokenV1 } from "./AbstractFiatTokenV1.sol";
                          import { Ownable } from "./Ownable.sol";
                          import { Pausable } from "./Pausable.sol";
                          import { Blacklistable } from "./Blacklistable.sol";
                          /**
                           * @title FiatToken
                           * @dev ERC20 Token backed by fiat reserves
                           */
                          contract FiatTokenV1 is AbstractFiatTokenV1, Ownable, Pausable, Blacklistable {
                              using SafeMath for uint256;
                              string public name;
                              string public symbol;
                              uint8 public decimals;
                              string public currency;
                              address public masterMinter;
                              bool internal initialized;
                              /// @dev A mapping that stores the balance and blacklist states for a given address.
                              /// The first bit defines whether the address is blacklisted (1 if blacklisted, 0 otherwise).
                              /// The last 255 bits define the balance for the address.
                              mapping(address => uint256) internal balanceAndBlacklistStates;
                              mapping(address => mapping(address => uint256)) internal allowed;
                              uint256 internal totalSupply_ = 0;
                              mapping(address => bool) internal minters;
                              mapping(address => uint256) internal minterAllowed;
                              event Mint(address indexed minter, address indexed to, uint256 amount);
                              event Burn(address indexed burner, uint256 amount);
                              event MinterConfigured(address indexed minter, uint256 minterAllowedAmount);
                              event MinterRemoved(address indexed oldMinter);
                              event MasterMinterChanged(address indexed newMasterMinter);
                              /**
                               * @notice Initializes the fiat token contract.
                               * @param tokenName       The name of the fiat token.
                               * @param tokenSymbol     The symbol of the fiat token.
                               * @param tokenCurrency   The fiat currency that the token represents.
                               * @param tokenDecimals   The number of decimals that the token uses.
                               * @param newMasterMinter The masterMinter address for the fiat token.
                               * @param newPauser       The pauser address for the fiat token.
                               * @param newBlacklister  The blacklister address for the fiat token.
                               * @param newOwner        The owner of the fiat token.
                               */
                              function initialize(
                                  string memory tokenName,
                                  string memory tokenSymbol,
                                  string memory tokenCurrency,
                                  uint8 tokenDecimals,
                                  address newMasterMinter,
                                  address newPauser,
                                  address newBlacklister,
                                  address newOwner
                              ) public {
                                  require(!initialized, "FiatToken: contract is already initialized");
                                  require(
                                      newMasterMinter != address(0),
                                      "FiatToken: new masterMinter is the zero address"
                                  );
                                  require(
                                      newPauser != address(0),
                                      "FiatToken: new pauser is the zero address"
                                  );
                                  require(
                                      newBlacklister != address(0),
                                      "FiatToken: new blacklister is the zero address"
                                  );
                                  require(
                                      newOwner != address(0),
                                      "FiatToken: new owner is the zero address"
                                  );
                                  name = tokenName;
                                  symbol = tokenSymbol;
                                  currency = tokenCurrency;
                                  decimals = tokenDecimals;
                                  masterMinter = newMasterMinter;
                                  pauser = newPauser;
                                  blacklister = newBlacklister;
                                  setOwner(newOwner);
                                  initialized = true;
                              }
                              /**
                               * @dev Throws if called by any account other than a minter.
                               */
                              modifier onlyMinters() {
                                  require(minters[msg.sender], "FiatToken: caller is not a minter");
                                  _;
                              }
                              /**
                               * @notice Mints fiat tokens to an address.
                               * @param _to The address that will receive the minted tokens.
                               * @param _amount The amount of tokens to mint. Must be less than or equal
                               * to the minterAllowance of the caller.
                               * @return True if the operation was successful.
                               */
                              function mint(address _to, uint256 _amount)
                                  external
                                  whenNotPaused
                                  onlyMinters
                                  notBlacklisted(msg.sender)
                                  notBlacklisted(_to)
                                  returns (bool)
                              {
                                  require(_to != address(0), "FiatToken: mint to the zero address");
                                  require(_amount > 0, "FiatToken: mint amount not greater than 0");
                                  uint256 mintingAllowedAmount = minterAllowed[msg.sender];
                                  require(
                                      _amount <= mintingAllowedAmount,
                                      "FiatToken: mint amount exceeds minterAllowance"
                                  );
                                  totalSupply_ = totalSupply_.add(_amount);
                                  _setBalance(_to, _balanceOf(_to).add(_amount));
                                  minterAllowed[msg.sender] = mintingAllowedAmount.sub(_amount);
                                  emit Mint(msg.sender, _to, _amount);
                                  emit Transfer(address(0), _to, _amount);
                                  return true;
                              }
                              /**
                               * @dev Throws if called by any account other than the masterMinter
                               */
                              modifier onlyMasterMinter() {
                                  require(
                                      msg.sender == masterMinter,
                                      "FiatToken: caller is not the masterMinter"
                                  );
                                  _;
                              }
                              /**
                               * @notice Gets the minter allowance for an account.
                               * @param minter The address to check.
                               * @return The remaining minter allowance for the account.
                               */
                              function minterAllowance(address minter) external view returns (uint256) {
                                  return minterAllowed[minter];
                              }
                              /**
                               * @notice Checks if an account is a minter.
                               * @param account The address to check.
                               * @return True if the account is a minter, false if the account is not a minter.
                               */
                              function isMinter(address account) external view returns (bool) {
                                  return minters[account];
                              }
                              /**
                               * @notice Gets the remaining amount of fiat tokens a spender is allowed to transfer on
                               * behalf of the token owner.
                               * @param owner   The token owner's address.
                               * @param spender The spender's address.
                               * @return The remaining allowance.
                               */
                              function allowance(address owner, address spender)
                                  external
                                  override
                                  view
                                  returns (uint256)
                              {
                                  return allowed[owner][spender];
                              }
                              /**
                               * @notice Gets the totalSupply of the fiat token.
                               * @return The totalSupply of the fiat token.
                               */
                              function totalSupply() external override view returns (uint256) {
                                  return totalSupply_;
                              }
                              /**
                               * @notice Gets the fiat token balance of an account.
                               * @param account  The address to check.
                               * @return balance The fiat token balance of the account.
                               */
                              function balanceOf(address account)
                                  external
                                  override
                                  view
                                  returns (uint256)
                              {
                                  return _balanceOf(account);
                              }
                              /**
                               * @notice Sets a fiat token allowance for a spender to spend on behalf of the caller.
                               * @param spender The spender's address.
                               * @param value   The allowance amount.
                               * @return True if the operation was successful.
                               */
                              function approve(address spender, uint256 value)
                                  external
                                  virtual
                                  override
                                  whenNotPaused
                                  notBlacklisted(msg.sender)
                                  notBlacklisted(spender)
                                  returns (bool)
                              {
                                  _approve(msg.sender, spender, value);
                                  return true;
                              }
                              /**
                               * @dev Internal function to set allowance.
                               * @param owner     Token owner's address.
                               * @param spender   Spender's address.
                               * @param value     Allowance amount.
                               */
                              function _approve(
                                  address owner,
                                  address spender,
                                  uint256 value
                              ) internal override {
                                  require(owner != address(0), "ERC20: approve from the zero address");
                                  require(spender != address(0), "ERC20: approve to the zero address");
                                  allowed[owner][spender] = value;
                                  emit Approval(owner, spender, value);
                              }
                              /**
                               * @notice Transfers tokens from an address to another by spending the caller's allowance.
                               * @dev The caller must have some fiat token allowance on the payer's tokens.
                               * @param from  Payer's address.
                               * @param to    Payee's address.
                               * @param value Transfer amount.
                               * @return True if the operation was successful.
                               */
                              function transferFrom(
                                  address from,
                                  address to,
                                  uint256 value
                              )
                                  external
                                  override
                                  whenNotPaused
                                  notBlacklisted(msg.sender)
                                  notBlacklisted(from)
                                  notBlacklisted(to)
                                  returns (bool)
                              {
                                  require(
                                      value <= allowed[from][msg.sender],
                                      "ERC20: transfer amount exceeds allowance"
                                  );
                                  _transfer(from, to, value);
                                  allowed[from][msg.sender] = allowed[from][msg.sender].sub(value);
                                  return true;
                              }
                              /**
                               * @notice Transfers tokens from the caller.
                               * @param to    Payee's address.
                               * @param value Transfer amount.
                               * @return True if the operation was successful.
                               */
                              function transfer(address to, uint256 value)
                                  external
                                  override
                                  whenNotPaused
                                  notBlacklisted(msg.sender)
                                  notBlacklisted(to)
                                  returns (bool)
                              {
                                  _transfer(msg.sender, to, value);
                                  return true;
                              }
                              /**
                               * @dev Internal function to process transfers.
                               * @param from  Payer's address.
                               * @param to    Payee's address.
                               * @param value Transfer amount.
                               */
                              function _transfer(
                                  address from,
                                  address to,
                                  uint256 value
                              ) internal override {
                                  require(from != address(0), "ERC20: transfer from the zero address");
                                  require(to != address(0), "ERC20: transfer to the zero address");
                                  require(
                                      value <= _balanceOf(from),
                                      "ERC20: transfer amount exceeds balance"
                                  );
                                  _setBalance(from, _balanceOf(from).sub(value));
                                  _setBalance(to, _balanceOf(to).add(value));
                                  emit Transfer(from, to, value);
                              }
                              /**
                               * @notice Adds or updates a new minter with a mint allowance.
                               * @param minter The address of the minter.
                               * @param minterAllowedAmount The minting amount allowed for the minter.
                               * @return True if the operation was successful.
                               */
                              function configureMinter(address minter, uint256 minterAllowedAmount)
                                  external
                                  whenNotPaused
                                  onlyMasterMinter
                                  returns (bool)
                              {
                                  minters[minter] = true;
                                  minterAllowed[minter] = minterAllowedAmount;
                                  emit MinterConfigured(minter, minterAllowedAmount);
                                  return true;
                              }
                              /**
                               * @notice Removes a minter.
                               * @param minter The address of the minter to remove.
                               * @return True if the operation was successful.
                               */
                              function removeMinter(address minter)
                                  external
                                  onlyMasterMinter
                                  returns (bool)
                              {
                                  minters[minter] = false;
                                  minterAllowed[minter] = 0;
                                  emit MinterRemoved(minter);
                                  return true;
                              }
                              /**
                               * @notice Allows a minter to burn some of its own tokens.
                               * @dev The caller must be a minter, must not be blacklisted, and the amount to burn
                               * should be less than or equal to the account's balance.
                               * @param _amount the amount of tokens to be burned.
                               */
                              function burn(uint256 _amount)
                                  external
                                  whenNotPaused
                                  onlyMinters
                                  notBlacklisted(msg.sender)
                              {
                                  uint256 balance = _balanceOf(msg.sender);
                                  require(_amount > 0, "FiatToken: burn amount not greater than 0");
                                  require(balance >= _amount, "FiatToken: burn amount exceeds balance");
                                  totalSupply_ = totalSupply_.sub(_amount);
                                  _setBalance(msg.sender, balance.sub(_amount));
                                  emit Burn(msg.sender, _amount);
                                  emit Transfer(msg.sender, address(0), _amount);
                              }
                              /**
                               * @notice Updates the master minter address.
                               * @param _newMasterMinter The address of the new master minter.
                               */
                              function updateMasterMinter(address _newMasterMinter) external onlyOwner {
                                  require(
                                      _newMasterMinter != address(0),
                                      "FiatToken: new masterMinter is the zero address"
                                  );
                                  masterMinter = _newMasterMinter;
                                  emit MasterMinterChanged(masterMinter);
                              }
                              /**
                               * @inheritdoc Blacklistable
                               */
                              function _blacklist(address _account) internal override {
                                  _setBlacklistState(_account, true);
                              }
                              /**
                               * @inheritdoc Blacklistable
                               */
                              function _unBlacklist(address _account) internal override {
                                  _setBlacklistState(_account, false);
                              }
                              /**
                               * @dev Helper method that sets the blacklist state of an account.
                               * @param _account         The address of the account.
                               * @param _shouldBlacklist True if the account should be blacklisted, false if the account should be unblacklisted.
                               */
                              function _setBlacklistState(address _account, bool _shouldBlacklist)
                                  internal
                                  virtual
                              {
                                  _deprecatedBlacklisted[_account] = _shouldBlacklist;
                              }
                              /**
                               * @dev Helper method that sets the balance of an account.
                               * @param _account The address of the account.
                               * @param _balance The new fiat token balance of the account.
                               */
                              function _setBalance(address _account, uint256 _balance) internal virtual {
                                  balanceAndBlacklistStates[_account] = _balance;
                              }
                              /**
                               * @inheritdoc Blacklistable
                               */
                              function _isBlacklisted(address _account)
                                  internal
                                  virtual
                                  override
                                  view
                                  returns (bool)
                              {
                                  return _deprecatedBlacklisted[_account];
                              }
                              /**
                               * @dev Helper method to obtain the balance of an account.
                               * @param _account  The address of the account.
                               * @return          The fiat token balance of the account.
                               */
                              function _balanceOf(address _account)
                                  internal
                                  virtual
                                  view
                                  returns (uint256)
                              {
                                  return balanceAndBlacklistStates[_account];
                              }
                          }
                          /**
                           * SPDX-License-Identifier: Apache-2.0
                           *
                           * Copyright (c) 2023, Circle Internet Financial, LLC.
                           *
                           * Licensed under the Apache License, Version 2.0 (the "License");
                           * you may not use this file except in compliance with the License.
                           * You may obtain a copy of the License at
                           *
                           * http://www.apache.org/licenses/LICENSE-2.0
                           *
                           * Unless required by applicable law or agreed to in writing, software
                           * distributed under the License is distributed on an "AS IS" BASIS,
                           * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
                           * See the License for the specific language governing permissions and
                           * limitations under the License.
                           */
                          pragma solidity 0.6.12;
                          import { Ownable } from "./Ownable.sol";
                          /**
                           * @title Blacklistable Token
                           * @dev Allows accounts to be blacklisted by a "blacklister" role
                           */
                          abstract contract Blacklistable is Ownable {
                              address public blacklister;
                              mapping(address => bool) internal _deprecatedBlacklisted;
                              event Blacklisted(address indexed _account);
                              event UnBlacklisted(address indexed _account);
                              event BlacklisterChanged(address indexed newBlacklister);
                              /**
                               * @dev Throws if called by any account other than the blacklister.
                               */
                              modifier onlyBlacklister() {
                                  require(
                                      msg.sender == blacklister,
                                      "Blacklistable: caller is not the blacklister"
                                  );
                                  _;
                              }
                              /**
                               * @dev Throws if argument account is blacklisted.
                               * @param _account The address to check.
                               */
                              modifier notBlacklisted(address _account) {
                                  require(
                                      !_isBlacklisted(_account),
                                      "Blacklistable: account is blacklisted"
                                  );
                                  _;
                              }
                              /**
                               * @notice Checks if account is blacklisted.
                               * @param _account The address to check.
                               * @return True if the account is blacklisted, false if the account is not blacklisted.
                               */
                              function isBlacklisted(address _account) external view returns (bool) {
                                  return _isBlacklisted(_account);
                              }
                              /**
                               * @notice Adds account to blacklist.
                               * @param _account The address to blacklist.
                               */
                              function blacklist(address _account) external onlyBlacklister {
                                  _blacklist(_account);
                                  emit Blacklisted(_account);
                              }
                              /**
                               * @notice Removes account from blacklist.
                               * @param _account The address to remove from the blacklist.
                               */
                              function unBlacklist(address _account) external onlyBlacklister {
                                  _unBlacklist(_account);
                                  emit UnBlacklisted(_account);
                              }
                              /**
                               * @notice Updates the blacklister address.
                               * @param _newBlacklister The address of the new blacklister.
                               */
                              function updateBlacklister(address _newBlacklister) external onlyOwner {
                                  require(
                                      _newBlacklister != address(0),
                                      "Blacklistable: new blacklister is the zero address"
                                  );
                                  blacklister = _newBlacklister;
                                  emit BlacklisterChanged(blacklister);
                              }
                              /**
                               * @dev Checks if account is blacklisted.
                               * @param _account The address to check.
                               * @return true if the account is blacklisted, false otherwise.
                               */
                              function _isBlacklisted(address _account)
                                  internal
                                  virtual
                                  view
                                  returns (bool);
                              /**
                               * @dev Helper method that blacklists an account.
                               * @param _account The address to blacklist.
                               */
                              function _blacklist(address _account) internal virtual;
                              /**
                               * @dev Helper method that unblacklists an account.
                               * @param _account The address to unblacklist.
                               */
                              function _unBlacklist(address _account) internal virtual;
                          }
                          /**
                           * SPDX-License-Identifier: Apache-2.0
                           *
                           * Copyright (c) 2023, Circle Internet Financial, LLC.
                           *
                           * Licensed under the Apache License, Version 2.0 (the "License");
                           * you may not use this file except in compliance with the License.
                           * You may obtain a copy of the License at
                           *
                           * http://www.apache.org/licenses/LICENSE-2.0
                           *
                           * Unless required by applicable law or agreed to in writing, software
                           * distributed under the License is distributed on an "AS IS" BASIS,
                           * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
                           * See the License for the specific language governing permissions and
                           * limitations under the License.
                           */
                          pragma solidity 0.6.12;
                          import { IERC20 } from "@openzeppelin/contracts/token/ERC20/IERC20.sol";
                          abstract contract AbstractFiatTokenV1 is IERC20 {
                              function _approve(
                                  address owner,
                                  address spender,
                                  uint256 value
                              ) internal virtual;
                              function _transfer(
                                  address from,
                                  address to,
                                  uint256 value
                              ) internal virtual;
                          }
                          /**
                           * SPDX-License-Identifier: Apache-2.0
                           *
                           * Copyright (c) 2023, Circle Internet Financial, LLC.
                           *
                           * Licensed under the Apache License, Version 2.0 (the "License");
                           * you may not use this file except in compliance with the License.
                           * You may obtain a copy of the License at
                           *
                           * http://www.apache.org/licenses/LICENSE-2.0
                           *
                           * Unless required by applicable law or agreed to in writing, software
                           * distributed under the License is distributed on an "AS IS" BASIS,
                           * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
                           * See the License for the specific language governing permissions and
                           * limitations under the License.
                           */
                          pragma solidity 0.6.12;
                          import { Ownable } from "../v1/Ownable.sol";
                          import { IERC20 } from "@openzeppelin/contracts/token/ERC20/IERC20.sol";
                          import { SafeERC20 } from "@openzeppelin/contracts/token/ERC20/SafeERC20.sol";
                          contract Rescuable is Ownable {
                              using SafeERC20 for IERC20;
                              address private _rescuer;
                              event RescuerChanged(address indexed newRescuer);
                              /**
                               * @notice Returns current rescuer
                               * @return Rescuer's address
                               */
                              function rescuer() external view returns (address) {
                                  return _rescuer;
                              }
                              /**
                               * @notice Revert if called by any account other than the rescuer.
                               */
                              modifier onlyRescuer() {
                                  require(msg.sender == _rescuer, "Rescuable: caller is not the rescuer");
                                  _;
                              }
                              /**
                               * @notice Rescue ERC20 tokens locked up in this contract.
                               * @param tokenContract ERC20 token contract address
                               * @param to        Recipient address
                               * @param amount    Amount to withdraw
                               */
                              function rescueERC20(
                                  IERC20 tokenContract,
                                  address to,
                                  uint256 amount
                              ) external onlyRescuer {
                                  tokenContract.safeTransfer(to, amount);
                              }
                              /**
                               * @notice Updates the rescuer address.
                               * @param newRescuer The address of the new rescuer.
                               */
                              function updateRescuer(address newRescuer) external onlyOwner {
                                  require(
                                      newRescuer != address(0),
                                      "Rescuable: new rescuer is the zero address"
                                  );
                                  _rescuer = newRescuer;
                                  emit RescuerChanged(newRescuer);
                              }
                          }
                          /**
                           * SPDX-License-Identifier: Apache-2.0
                           *
                           * Copyright (c) 2023, Circle Internet Financial, LLC.
                           *
                           * Licensed under the Apache License, Version 2.0 (the "License");
                           * you may not use this file except in compliance with the License.
                           * You may obtain a copy of the License at
                           *
                           * http://www.apache.org/licenses/LICENSE-2.0
                           *
                           * Unless required by applicable law or agreed to in writing, software
                           * distributed under the License is distributed on an "AS IS" BASIS,
                           * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
                           * See the License for the specific language governing permissions and
                           * limitations under the License.
                           */
                          pragma solidity 0.6.12;
                          import { FiatTokenV1 } from "../v1/FiatTokenV1.sol";
                          import { Rescuable } from "./Rescuable.sol";
                          /**
                           * @title FiatTokenV1_1
                           * @dev ERC20 Token backed by fiat reserves
                           */
                          contract FiatTokenV1_1 is FiatTokenV1, Rescuable {
                          }
                          /**
                           * SPDX-License-Identifier: Apache-2.0
                           *
                           * Copyright (c) 2023, Circle Internet Financial, LLC.
                           *
                           * Licensed under the Apache License, Version 2.0 (the "License");
                           * you may not use this file except in compliance with the License.
                           * You may obtain a copy of the License at
                           *
                           * http://www.apache.org/licenses/LICENSE-2.0
                           *
                           * Unless required by applicable law or agreed to in writing, software
                           * distributed under the License is distributed on an "AS IS" BASIS,
                           * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
                           * See the License for the specific language governing permissions and
                           * limitations under the License.
                           */
                          pragma solidity 0.6.12;
                          import { ECRecover } from "./ECRecover.sol";
                          import { IERC1271 } from "../interface/IERC1271.sol";
                          /**
                           * @dev Signature verification helper that can be used instead of `ECRecover.recover` to seamlessly support both ECDSA
                           * signatures from externally owned accounts (EOAs) as well as ERC1271 signatures from smart contract wallets.
                           *
                           * Adapted from https://github.com/OpenZeppelin/openzeppelin-contracts/blob/21bb89ef5bfc789b9333eb05e3ba2b7b284ac77c/contracts/utils/cryptography/SignatureChecker.sol
                           */
                          library SignatureChecker {
                              /**
                               * @dev Checks if a signature is valid for a given signer and data hash. If the signer is a smart contract, the
                               * signature is validated against that smart contract using ERC1271, otherwise it's validated using `ECRecover.recover`.
                               * @param signer        Address of the claimed signer
                               * @param digest        Keccak-256 hash digest of the signed message
                               * @param signature     Signature byte array associated with hash
                               */
                              function isValidSignatureNow(
                                  address signer,
                                  bytes32 digest,
                                  bytes memory signature
                              ) external view returns (bool) {
                                  if (!isContract(signer)) {
                                      return ECRecover.recover(digest, signature) == signer;
                                  }
                                  return isValidERC1271SignatureNow(signer, digest, signature);
                              }
                              /**
                               * @dev Checks if a signature is valid for a given signer and data hash. The signature is validated
                               * against the signer smart contract using ERC1271.
                               * @param signer        Address of the claimed signer
                               * @param digest        Keccak-256 hash digest of the signed message
                               * @param signature     Signature byte array associated with hash
                               *
                               * NOTE: Unlike ECDSA signatures, contract signatures are revocable, and the outcome of this function can thus
                               * change through time. It could return true at block N and false at block N+1 (or the opposite).
                               */
                              function isValidERC1271SignatureNow(
                                  address signer,
                                  bytes32 digest,
                                  bytes memory signature
                              ) internal view returns (bool) {
                                  (bool success, bytes memory result) = signer.staticcall(
                                      abi.encodeWithSelector(
                                          IERC1271.isValidSignature.selector,
                                          digest,
                                          signature
                                      )
                                  );
                                  return (success &&
                                      result.length >= 32 &&
                                      abi.decode(result, (bytes32)) ==
                                      bytes32(IERC1271.isValidSignature.selector));
                              }
                              /**
                               * @dev Checks if the input address is a smart contract.
                               */
                              function isContract(address addr) internal view returns (bool) {
                                  uint256 size;
                                  assembly {
                                      size := extcodesize(addr)
                                  }
                                  return size > 0;
                              }
                          }
                          /**
                           * SPDX-License-Identifier: Apache-2.0
                           *
                           * Copyright (c) 2023, Circle Internet Financial, LLC.
                           *
                           * Licensed under the Apache License, Version 2.0 (the "License");
                           * you may not use this file except in compliance with the License.
                           * You may obtain a copy of the License at
                           *
                           * http://www.apache.org/licenses/LICENSE-2.0
                           *
                           * Unless required by applicable law or agreed to in writing, software
                           * distributed under the License is distributed on an "AS IS" BASIS,
                           * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
                           * See the License for the specific language governing permissions and
                           * limitations under the License.
                           */
                          pragma solidity 0.6.12;
                          /**
                           * @dev Signature message hash utilities for producing digests to be consumed by {ECDSA} recovery or signing.
                           *
                           * The library provides methods for generating a hash of a message that conforms to the
                           * https://eips.ethereum.org/EIPS/eip-191[EIP 191] and https://eips.ethereum.org/EIPS/eip-712[EIP 712]
                           * specifications.
                           */
                          library MessageHashUtils {
                              /**
                               * @dev Returns the keccak256 digest of an EIP-712 typed data (EIP-191 version `0x01`).
                               * Adapted from https://github.com/OpenZeppelin/openzeppelin-contracts/blob/21bb89ef5bfc789b9333eb05e3ba2b7b284ac77c/contracts/utils/cryptography/MessageHashUtils.sol
                               *
                               * The digest is calculated from a `domainSeparator` and a `structHash`, by prefixing them with
                               * `\\x19\\x01` and hashing the result. It corresponds to the hash signed by the
                               * https://eips.ethereum.org/EIPS/eip-712[`eth_signTypedData`] JSON-RPC method as part of EIP-712.
                               *
                               * @param domainSeparator    Domain separator
                               * @param structHash         Hashed EIP-712 data struct
                               * @return digest            The keccak256 digest of an EIP-712 typed data
                               */
                              function toTypedDataHash(bytes32 domainSeparator, bytes32 structHash)
                                  internal
                                  pure
                                  returns (bytes32 digest)
                              {
                                  assembly {
                                      let ptr := mload(0x40)
                                      mstore(ptr, "\\x19\\x01")
                                      mstore(add(ptr, 0x02), domainSeparator)
                                      mstore(add(ptr, 0x22), structHash)
                                      digest := keccak256(ptr, 0x42)
                                  }
                              }
                          }
                          /**
                           * SPDX-License-Identifier: Apache-2.0
                           *
                           * Copyright (c) 2023, Circle Internet Financial, LLC.
                           *
                           * Licensed under the Apache License, Version 2.0 (the "License");
                           * you may not use this file except in compliance with the License.
                           * You may obtain a copy of the License at
                           *
                           * http://www.apache.org/licenses/LICENSE-2.0
                           *
                           * Unless required by applicable law or agreed to in writing, software
                           * distributed under the License is distributed on an "AS IS" BASIS,
                           * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
                           * See the License for the specific language governing permissions and
                           * limitations under the License.
                           */
                          pragma solidity 0.6.12;
                          /**
                           * @title EIP712
                           * @notice A library that provides EIP712 helper functions
                           */
                          library EIP712 {
                              /**
                               * @notice Make EIP712 domain separator
                               * @param name      Contract name
                               * @param version   Contract version
                               * @param chainId   Blockchain ID
                               * @return Domain separator
                               */
                              function makeDomainSeparator(
                                  string memory name,
                                  string memory version,
                                  uint256 chainId
                              ) internal view returns (bytes32) {
                                  return
                                      keccak256(
                                          abi.encode(
                                              // keccak256("EIP712Domain(string name,string version,uint256 chainId,address verifyingContract)")
                                              0x8b73c3c69bb8fe3d512ecc4cf759cc79239f7b179b0ffacaa9a75d522b39400f,
                                              keccak256(bytes(name)),
                                              keccak256(bytes(version)),
                                              chainId,
                                              address(this)
                                          )
                                      );
                              }
                              /**
                               * @notice Make EIP712 domain separator
                               * @param name      Contract name
                               * @param version   Contract version
                               * @return Domain separator
                               */
                              function makeDomainSeparator(string memory name, string memory version)
                                  internal
                                  view
                                  returns (bytes32)
                              {
                                  uint256 chainId;
                                  assembly {
                                      chainId := chainid()
                                  }
                                  return makeDomainSeparator(name, version, chainId);
                              }
                          }
                          /**
                           * SPDX-License-Identifier: Apache-2.0
                           *
                           * Copyright (c) 2023, Circle Internet Financial, LLC.
                           *
                           * Licensed under the Apache License, Version 2.0 (the "License");
                           * you may not use this file except in compliance with the License.
                           * You may obtain a copy of the License at
                           *
                           * http://www.apache.org/licenses/LICENSE-2.0
                           *
                           * Unless required by applicable law or agreed to in writing, software
                           * distributed under the License is distributed on an "AS IS" BASIS,
                           * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
                           * See the License for the specific language governing permissions and
                           * limitations under the License.
                           */
                          pragma solidity 0.6.12;
                          /**
                           * @title ECRecover
                           * @notice A library that provides a safe ECDSA recovery function
                           */
                          library ECRecover {
                              /**
                               * @notice Recover signer's address from a signed message
                               * @dev Adapted from: https://github.com/OpenZeppelin/openzeppelin-contracts/blob/65e4ffde586ec89af3b7e9140bdc9235d1254853/contracts/cryptography/ECDSA.sol
                               * Modifications: Accept v, r, and s as separate arguments
                               * @param digest    Keccak-256 hash digest of the signed message
                               * @param v         v of the signature
                               * @param r         r of the signature
                               * @param s         s of the signature
                               * @return Signer address
                               */
                              function recover(
                                  bytes32 digest,
                                  uint8 v,
                                  bytes32 r,
                                  bytes32 s
                              ) internal pure returns (address) {
                                  // EIP-2 still allows signature malleability for ecrecover(). Remove this possibility and make the signature
                                  // unique. Appendix F in the Ethereum Yellow paper (https://ethereum.github.io/yellowpaper/paper.pdf), defines
                                  // the valid range for s in (281): 0 < s < secp256k1n ÷ 2 + 1, and for v in (282): v ∈ {27, 28}. Most
                                  // signatures from current libraries generate a unique signature with an s-value in the lower half order.
                                  //
                                  // If your library generates malleable signatures, such as s-values in the upper range, calculate a new s-value
                                  // with 0xFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFEBAAEDCE6AF48A03BBFD25E8CD0364141 - s1 and flip v from 27 to 28 or
                                  // vice versa. If your library also generates signatures with 0/1 for v instead 27/28, add 27 to v to accept
                                  // these malleable signatures as well.
                                  if (
                                      uint256(s) >
                                      0x7FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF5D576E7357A4501DDFE92F46681B20A0
                                  ) {
                                      revert("ECRecover: invalid signature 's' value");
                                  }
                                  if (v != 27 && v != 28) {
                                      revert("ECRecover: invalid signature 'v' value");
                                  }
                                  // If the signature is valid (and not malleable), return the signer address
                                  address signer = ecrecover(digest, v, r, s);
                                  require(signer != address(0), "ECRecover: invalid signature");
                                  return signer;
                              }
                              /**
                               * @notice Recover signer's address from a signed message
                               * @dev Adapted from: https://github.com/OpenZeppelin/openzeppelin-contracts/blob/0053ee040a7ff1dbc39691c9e67a69f564930a88/contracts/utils/cryptography/ECDSA.sol
                               * @param digest    Keccak-256 hash digest of the signed message
                               * @param signature Signature byte array associated with hash
                               * @return Signer address
                               */
                              function recover(bytes32 digest, bytes memory signature)
                                  internal
                                  pure
                                  returns (address)
                              {
                                  require(signature.length == 65, "ECRecover: invalid signature length");
                                  bytes32 r;
                                  bytes32 s;
                                  uint8 v;
                                  // ecrecover takes the signature parameters, and the only way to get them
                                  // currently is to use assembly.
                                  /// @solidity memory-safe-assembly
                                  assembly {
                                      r := mload(add(signature, 0x20))
                                      s := mload(add(signature, 0x40))
                                      v := byte(0, mload(add(signature, 0x60)))
                                  }
                                  return recover(digest, v, r, s);
                              }
                          }
                          /**
                           * SPDX-License-Identifier: Apache-2.0
                           *
                           * Copyright (c) 2023, Circle Internet Financial, LLC.
                           *
                           * Licensed under the Apache License, Version 2.0 (the "License");
                           * you may not use this file except in compliance with the License.
                           * You may obtain a copy of the License at
                           *
                           * http://www.apache.org/licenses/LICENSE-2.0
                           *
                           * Unless required by applicable law or agreed to in writing, software
                           * distributed under the License is distributed on an "AS IS" BASIS,
                           * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
                           * See the License for the specific language governing permissions and
                           * limitations under the License.
                           */
                          pragma solidity 0.6.12;
                          /**
                           * @dev Interface of the ERC1271 standard signature validation method for
                           * contracts as defined in https://eips.ethereum.org/EIPS/eip-1271[ERC-1271].
                           */
                          interface IERC1271 {
                              /**
                               * @dev Should return whether the signature provided is valid for the provided data
                               * @param hash          Hash of the data to be signed
                               * @param signature     Signature byte array associated with the provided data hash
                               * @return magicValue   bytes4 magic value 0x1626ba7e when function passes
                               */
                              function isValidSignature(bytes32 hash, bytes memory signature)
                                  external
                                  view
                                  returns (bytes4 magicValue);
                          }