ETH Price: $2,291.05 (+4.93%)

Transaction Decoder

Block:
17983296 at Aug-24-2023 08:12:59 AM +UTC
Transaction Fee:
0.004421297336065727 ETH $10.13
Gas Used:
288,119 Gas / 15.345386233 Gwei

Emitted Events:

153 Nishikigoi.Transfer( from=0x00000000...000000000, to=[Receiver] Minter, tokenId=5570 )
154 Nishikigoi.Transfer( from=0x00000000...000000000, to=[Receiver] Minter, tokenId=7733 )
155 Nishikigoi.Approval( owner=[Receiver] Minter, approved=0x00000000...000000000, tokenId=5570 )
156 Nishikigoi.Transfer( from=[Receiver] Minter, to=0xCB8bD823...72FbDE02C, tokenId=5570 )
157 Nishikigoi.Approval( owner=0xCB8bD823...72FbDE02C, approved=0x00000000...000000000, tokenId=5570 )
158 Nishikigoi.Transfer( from=0xCB8bD823...72FbDE02C, to=[Sender] 0x342c5b5e88313485d9e041db4fdfa8dfe26a4eec, tokenId=5570 )
159 Minter.Minted( _tokenId=5570, _artist=2, _seed=166000F66E7CEEBD92D9B89024C3F09C453FAA531DE7CDEFDF27D8FEFA7DC19D )
160 Nishikigoi.Approval( owner=[Receiver] Minter, approved=0x00000000...000000000, tokenId=7733 )
161 Nishikigoi.Transfer( from=[Receiver] Minter, to=0xCB8bD823...72FbDE02C, tokenId=7733 )
162 Nishikigoi.Approval( owner=0xCB8bD823...72FbDE02C, approved=0x00000000...000000000, tokenId=7733 )
163 Nishikigoi.Transfer( from=0xCB8bD823...72FbDE02C, to=[Sender] 0x342c5b5e88313485d9e041db4fdfa8dfe26a4eec, tokenId=7733 )
164 Minter.Minted( _tokenId=7733, _artist=2, _seed=1D7C1A6F6AE926BBA68CA44EB1F155C9C53DC17747A0A6CE17E2BB8B0231C821 )

Account State Difference:

  Address   Before After State Difference Code
0x08F09552...84E1b0ff3
0x342C5b5E...Fe26A4EEc
0.088410777129519384 Eth
Nonce: 416
0.023989479793453657 Eth
Nonce: 417
0.064421297336065727
(blockbeelder)
0.045356767810715357 Eth0.045385579710715357 Eth0.0000288119
0xF16a5B64...00FB6469a 19.17 Eth19.23 Eth0.06

Execution Trace

ETH 0.06 Minter.publicMint( _tokenIdList=[5570, 7733] )
  • Nishikigoi.updateSaleStatus( __isOnSale=True )
  • ETH 0.06 Nishikigoi.buyBundle( tokenIdList=[5570, 7733] )
    • Minter.onERC721Received( 0x08F095520BBC7aB9F8351A1bf7f8c0084E1b0ff3, 0x0000000000000000000000000000000000000000, 5570, 0x )
    • Minter.onERC721Received( 0x08F095520BBC7aB9F8351A1bf7f8c0084E1b0ff3, 0x0000000000000000000000000000000000000000, 7733, 0x )
    • Nishikigoi.updateSaleStatus( __isOnSale=False )
    • Nishikigoi.safeTransferFrom( from=0x08F095520BBC7aB9F8351A1bf7f8c0084E1b0ff3, to=0xCB8bD8239072f118E09daa7d3B7B12372FbDE02C, tokenId=5570 )
    • Nishikigoi.safeTransferFrom( from=0xCB8bD8239072f118E09daa7d3B7B12372FbDE02C, to=0x342C5b5E88313485d9e041dB4FDFA8dFe26A4EEc, tokenId=5570 )
    • Nishikigoi.safeTransferFrom( from=0x08F095520BBC7aB9F8351A1bf7f8c0084E1b0ff3, to=0xCB8bD8239072f118E09daa7d3B7B12372FbDE02C, tokenId=7733 )
    • Nishikigoi.safeTransferFrom( from=0xCB8bD8239072f118E09daa7d3B7B12372FbDE02C, to=0x342C5b5E88313485d9e041dB4FDFA8dFe26A4EEc, tokenId=7733 )
      publicMint[Minter (ln:683)]
      File 1 of 2: Minter
      // SPDX-License-Identifier: MIT
      // OpenZeppelin Contracts (last updated v4.7.0) (access/Ownable.sol)
      pragma solidity ^0.8.0;
      import "../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.
       *
       * By default, the owner account will be the one that deploys the contract. 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;
          event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);
          /**
           * @dev Initializes the contract setting the deployer as the initial owner.
           */
          constructor() {
              _transferOwnership(_msgSender());
          }
          /**
           * @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 {
              require(owner() == _msgSender(), "Ownable: caller is not the owner");
          }
          /**
           * @dev Leaves the contract without owner. It will not be possible to call
           * `onlyOwner` functions anymore. Can only be called by the current owner.
           *
           * NOTE: Renouncing ownership will leave the contract without an owner,
           * thereby removing 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 {
              require(newOwner != address(0), "Ownable: new owner is the zero address");
              _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 v4.8.0) (security/ReentrancyGuard.sol)
      pragma solidity ^0.8.0;
      /**
       * @dev Contract module that helps prevent reentrant calls to a function.
       *
       * Inheriting from `ReentrancyGuard` will make the {nonReentrant} modifier
       * available, which can be applied to functions to make sure there are no nested
       * (reentrant) calls to them.
       *
       * Note that because there is a single `nonReentrant` guard, functions marked as
       * `nonReentrant` may not call one another. This can be worked around by making
       * those functions `private`, and then adding `external` `nonReentrant` entry
       * points to them.
       *
       * TIP: If you would like to learn more about reentrancy and alternative ways
       * to protect against it, check out our blog post
       * https://blog.openzeppelin.com/reentrancy-after-istanbul/[Reentrancy After Istanbul].
       */
      abstract contract ReentrancyGuard {
          // Booleans are more expensive than uint256 or any type that takes up a full
          // word because each write operation emits an extra SLOAD to first read the
          // slot's contents, replace the bits taken up by the boolean, and then write
          // back. This is the compiler's defense against contract upgrades and
          // pointer aliasing, and it cannot be disabled.
          // The values being non-zero value makes deployment a bit more expensive,
          // but in exchange the refund on every call to nonReentrant will be lower in
          // amount. Since refunds are capped to a percentage of the total
          // transaction's gas, it is best to keep them low in cases like this one, to
          // increase the likelihood of the full refund coming into effect.
          uint256 private constant _NOT_ENTERED = 1;
          uint256 private constant _ENTERED = 2;
          uint256 private _status;
          constructor() {
              _status = _NOT_ENTERED;
          }
          /**
           * @dev Prevents a contract from calling itself, directly or indirectly.
           * Calling a `nonReentrant` function from another `nonReentrant`
           * function is not supported. It is possible to prevent this from happening
           * by making the `nonReentrant` function external, and making it call a
           * `private` function that does the actual work.
           */
          modifier nonReentrant() {
              _nonReentrantBefore();
              _;
              _nonReentrantAfter();
          }
          function _nonReentrantBefore() private {
              // On the first call to nonReentrant, _status will be _NOT_ENTERED
              require(_status != _ENTERED, "ReentrancyGuard: reentrant call");
              // Any calls to nonReentrant after this point will fail
              _status = _ENTERED;
          }
          function _nonReentrantAfter() private {
              // By storing the original value once again, a refund is triggered (see
              // https://eips.ethereum.org/EIPS/eip-2200)
              _status = _NOT_ENTERED;
          }
      }
      // SPDX-License-Identifier: MIT
      // OpenZeppelin Contracts (last updated v4.6.0) (token/ERC721/IERC721Receiver.sol)
      pragma solidity ^0.8.0;
      /**
       * @title ERC721 token receiver interface
       * @dev Interface for any contract that wants to support safeTransfers
       * from ERC721 asset contracts.
       */
      interface IERC721Receiver {
          /**
           * @dev Whenever an {IERC721} `tokenId` token is transferred to this contract via {IERC721-safeTransferFrom}
           * by `operator` from `from`, this function is called.
           *
           * It must return its Solidity selector to confirm the token transfer.
           * If any other value is returned or the interface is not implemented by the recipient, the transfer will be reverted.
           *
           * The selector can be obtained in Solidity with `IERC721Receiver.onERC721Received.selector`.
           */
          function onERC721Received(
              address operator,
              address from,
              uint256 tokenId,
              bytes calldata data
          ) external returns (bytes4);
      }
      // SPDX-License-Identifier: MIT
      // OpenZeppelin Contracts (last updated v4.8.0) (utils/Address.sol)
      pragma solidity ^0.8.1;
      /**
       * @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
           * ====
           *
           * [IMPORTANT]
           * ====
           * You shouldn't rely on `isContract` to protect against flash loan attacks!
           *
           * Preventing calls from contracts is highly discouraged. It breaks composability, breaks support for smart wallets
           * like Gnosis Safe, and does not provide security since it can be circumvented by calling from a contract
           * constructor.
           * ====
           */
          function isContract(address account) internal view returns (bool) {
              // This method relies on extcodesize/address.code.length, which returns 0
              // for contracts in construction, since the code is only stored at the end
              // of the constructor execution.
              return account.code.length > 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");
              (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 functionCallWithValue(target, data, 0, "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");
              (bool success, bytes memory returndata) = target.call{value: value}(data);
              return verifyCallResultFromTarget(target, 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) {
              (bool success, bytes memory returndata) = target.staticcall(data);
              return verifyCallResultFromTarget(target, 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) {
              (bool success, bytes memory returndata) = target.delegatecall(data);
              return verifyCallResultFromTarget(target, success, returndata, errorMessage);
          }
          /**
           * @dev Tool to verify that a low level call to smart-contract was successful, and revert (either by bubbling
           * the revert reason or using the provided one) in case of unsuccessful call or if target was not a contract.
           *
           * _Available since v4.8._
           */
          function verifyCallResultFromTarget(
              address target,
              bool success,
              bytes memory returndata,
              string memory errorMessage
          ) internal view returns (bytes memory) {
              if (success) {
                  if (returndata.length == 0) {
                      // only check isContract if the call was successful and the return data is empty
                      // otherwise we already know that it was a contract
                      require(isContract(target), "Address: call to non-contract");
                  }
                  return returndata;
              } else {
                  _revert(returndata, errorMessage);
              }
          }
          /**
           * @dev Tool to verify that a low level call was successful, and revert if it wasn't, either by bubbling the
           * revert reason or using the provided one.
           *
           * _Available since v4.3._
           */
          function verifyCallResult(
              bool success,
              bytes memory returndata,
              string memory errorMessage
          ) internal pure returns (bytes memory) {
              if (success) {
                  return returndata;
              } else {
                  _revert(returndata, errorMessage);
              }
          }
          function _revert(bytes memory returndata, string memory errorMessage) 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(errorMessage);
              }
          }
      }
      // SPDX-License-Identifier: MIT
      // OpenZeppelin Contracts v4.4.1 (utils/Context.sol)
      pragma solidity ^0.8.0;
      /**
       * @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;
          }
      }
      // SPDX-License-Identifier: MIT
      // OpenZeppelin Contracts (last updated v4.8.0) (utils/cryptography/MerkleProof.sol)
      pragma solidity ^0.8.0;
      /**
       * @dev These functions deal with verification of Merkle Tree proofs.
       *
       * The tree and the proofs can be generated using our
       * https://github.com/OpenZeppelin/merkle-tree[JavaScript library].
       * You will find a quickstart guide in the readme.
       *
       * WARNING: You should avoid using leaf values that are 64 bytes long prior to
       * hashing, or use a hash function other than keccak256 for hashing leaves.
       * This is because the concatenation of a sorted pair of internal nodes in
       * the merkle tree could be reinterpreted as a leaf value.
       * OpenZeppelin's JavaScript library generates merkle trees that are safe
       * against this attack out of the box.
       */
      library MerkleProof {
          /**
           * @dev Returns true if a `leaf` can be proved to be a part of a Merkle tree
           * defined by `root`. For this, a `proof` must be provided, containing
           * sibling hashes on the branch from the leaf to the root of the tree. Each
           * pair of leaves and each pair of pre-images are assumed to be sorted.
           */
          function verify(
              bytes32[] memory proof,
              bytes32 root,
              bytes32 leaf
          ) internal pure returns (bool) {
              return processProof(proof, leaf) == root;
          }
          /**
           * @dev Calldata version of {verify}
           *
           * _Available since v4.7._
           */
          function verifyCalldata(
              bytes32[] calldata proof,
              bytes32 root,
              bytes32 leaf
          ) internal pure returns (bool) {
              return processProofCalldata(proof, leaf) == root;
          }
          /**
           * @dev Returns the rebuilt hash obtained by traversing a Merkle tree up
           * from `leaf` using `proof`. A `proof` is valid if and only if the rebuilt
           * hash matches the root of the tree. When processing the proof, the pairs
           * of leafs & pre-images are assumed to be sorted.
           *
           * _Available since v4.4._
           */
          function processProof(bytes32[] memory proof, bytes32 leaf) internal pure returns (bytes32) {
              bytes32 computedHash = leaf;
              for (uint256 i = 0; i < proof.length; i++) {
                  computedHash = _hashPair(computedHash, proof[i]);
              }
              return computedHash;
          }
          /**
           * @dev Calldata version of {processProof}
           *
           * _Available since v4.7._
           */
          function processProofCalldata(bytes32[] calldata proof, bytes32 leaf) internal pure returns (bytes32) {
              bytes32 computedHash = leaf;
              for (uint256 i = 0; i < proof.length; i++) {
                  computedHash = _hashPair(computedHash, proof[i]);
              }
              return computedHash;
          }
          /**
           * @dev Returns true if the `leaves` can be simultaneously proven to be a part of a merkle tree defined by
           * `root`, according to `proof` and `proofFlags` as described in {processMultiProof}.
           *
           * CAUTION: Not all merkle trees admit multiproofs. See {processMultiProof} for details.
           *
           * _Available since v4.7._
           */
          function multiProofVerify(
              bytes32[] memory proof,
              bool[] memory proofFlags,
              bytes32 root,
              bytes32[] memory leaves
          ) internal pure returns (bool) {
              return processMultiProof(proof, proofFlags, leaves) == root;
          }
          /**
           * @dev Calldata version of {multiProofVerify}
           *
           * CAUTION: Not all merkle trees admit multiproofs. See {processMultiProof} for details.
           *
           * _Available since v4.7._
           */
          function multiProofVerifyCalldata(
              bytes32[] calldata proof,
              bool[] calldata proofFlags,
              bytes32 root,
              bytes32[] memory leaves
          ) internal pure returns (bool) {
              return processMultiProofCalldata(proof, proofFlags, leaves) == root;
          }
          /**
           * @dev Returns the root of a tree reconstructed from `leaves` and sibling nodes in `proof`. The reconstruction
           * proceeds by incrementally reconstructing all inner nodes by combining a leaf/inner node with either another
           * leaf/inner node or a proof sibling node, depending on whether each `proofFlags` item is true or false
           * respectively.
           *
           * CAUTION: Not all merkle trees admit multiproofs. To use multiproofs, it is sufficient to ensure that: 1) the tree
           * is complete (but not necessarily perfect), 2) the leaves to be proven are in the opposite order they are in the
           * tree (i.e., as seen from right to left starting at the deepest layer and continuing at the next layer).
           *
           * _Available since v4.7._
           */
          function processMultiProof(
              bytes32[] memory proof,
              bool[] memory proofFlags,
              bytes32[] memory leaves
          ) internal pure returns (bytes32 merkleRoot) {
              // This function rebuild the root hash by traversing the tree up from the leaves. The root is rebuilt by
              // consuming and producing values on a queue. The queue starts with the `leaves` array, then goes onto the
              // `hashes` array. At the end of the process, the last hash in the `hashes` array should contain the root of
              // the merkle tree.
              uint256 leavesLen = leaves.length;
              uint256 totalHashes = proofFlags.length;
              // Check proof validity.
              require(leavesLen + proof.length - 1 == totalHashes, "MerkleProof: invalid multiproof");
              // The xxxPos values are "pointers" to the next value to consume in each array. All accesses are done using
              // `xxx[xxxPos++]`, which return the current value and increment the pointer, thus mimicking a queue's "pop".
              bytes32[] memory hashes = new bytes32[](totalHashes);
              uint256 leafPos = 0;
              uint256 hashPos = 0;
              uint256 proofPos = 0;
              // At each step, we compute the next hash using two values:
              // - a value from the "main queue". If not all leaves have been consumed, we get the next leaf, otherwise we
              //   get the next hash.
              // - depending on the flag, either another value for the "main queue" (merging branches) or an element from the
              //   `proof` array.
              for (uint256 i = 0; i < totalHashes; i++) {
                  bytes32 a = leafPos < leavesLen ? leaves[leafPos++] : hashes[hashPos++];
                  bytes32 b = proofFlags[i] ? leafPos < leavesLen ? leaves[leafPos++] : hashes[hashPos++] : proof[proofPos++];
                  hashes[i] = _hashPair(a, b);
              }
              if (totalHashes > 0) {
                  return hashes[totalHashes - 1];
              } else if (leavesLen > 0) {
                  return leaves[0];
              } else {
                  return proof[0];
              }
          }
          /**
           * @dev Calldata version of {processMultiProof}.
           *
           * CAUTION: Not all merkle trees admit multiproofs. See {processMultiProof} for details.
           *
           * _Available since v4.7._
           */
          function processMultiProofCalldata(
              bytes32[] calldata proof,
              bool[] calldata proofFlags,
              bytes32[] memory leaves
          ) internal pure returns (bytes32 merkleRoot) {
              // This function rebuild the root hash by traversing the tree up from the leaves. The root is rebuilt by
              // consuming and producing values on a queue. The queue starts with the `leaves` array, then goes onto the
              // `hashes` array. At the end of the process, the last hash in the `hashes` array should contain the root of
              // the merkle tree.
              uint256 leavesLen = leaves.length;
              uint256 totalHashes = proofFlags.length;
              // Check proof validity.
              require(leavesLen + proof.length - 1 == totalHashes, "MerkleProof: invalid multiproof");
              // The xxxPos values are "pointers" to the next value to consume in each array. All accesses are done using
              // `xxx[xxxPos++]`, which return the current value and increment the pointer, thus mimicking a queue's "pop".
              bytes32[] memory hashes = new bytes32[](totalHashes);
              uint256 leafPos = 0;
              uint256 hashPos = 0;
              uint256 proofPos = 0;
              // At each step, we compute the next hash using two values:
              // - a value from the "main queue". If not all leaves have been consumed, we get the next leaf, otherwise we
              //   get the next hash.
              // - depending on the flag, either another value for the "main queue" (merging branches) or an element from the
              //   `proof` array.
              for (uint256 i = 0; i < totalHashes; i++) {
                  bytes32 a = leafPos < leavesLen ? leaves[leafPos++] : hashes[hashPos++];
                  bytes32 b = proofFlags[i] ? leafPos < leavesLen ? leaves[leafPos++] : hashes[hashPos++] : proof[proofPos++];
                  hashes[i] = _hashPair(a, b);
              }
              if (totalHashes > 0) {
                  return hashes[totalHashes - 1];
              } else if (leavesLen > 0) {
                  return leaves[0];
              } else {
                  return proof[0];
              }
          }
          function _hashPair(bytes32 a, bytes32 b) private pure returns (bytes32) {
              return a < b ? _efficientHash(a, b) : _efficientHash(b, a);
          }
          function _efficientHash(bytes32 a, bytes32 b) private pure returns (bytes32 value) {
              /// @solidity memory-safe-assembly
              assembly {
                  mstore(0x00, a)
                  mstore(0x20, b)
                  value := keccak256(0x00, 0x40)
              }
          }
      }
      // SPDX-License-Identifier: MIT
      pragma solidity ^0.8.17;
      interface INishikigoi {
          // functions of target contract
          function mintedSalesTokenIdList(
              uint256 offset,
              uint256 limit
          ) external view returns (uint256[] memory);
          function buy(uint256 tokenId) external payable;
          function buyBundle(uint256[] memory tokenIdList) external payable;
          function updateSaleStatus(bool _isOnSale) external;
          function updateBaseURI(string calldata newBaseURI) external;
          function mintForPromotion(address to, uint256 amount) external;
          function withdrawETH() external;
          function transferOwnership(address newOwner) external;
          // functions for ERC721
          /**
           * @dev Safely transfers `tokenId` token from `from` to `to`, checking first that contract recipients
           * are aware of the ERC721 protocol to prevent tokens from being forever locked.
           *
           * Requirements:
           *
           * - `from` cannot be the zero address.
           * - `to` cannot be the zero address.
           * - `tokenId` token must exist and be owned by `from`.
           * - If the caller is not `from`, it must have been allowed to move this token by either {approve} or {setApprovalForAll}.
           * - If `to` refers to a smart contract, it must implement {IERC721Receiver-onERC721Received}, which is called upon a safe transfer.
           *
           * Emits a {Transfer} event.
           */
          function safeTransferFrom(
              address from,
              address to,
              uint256 tokenId
          ) external;
      }// SPDX-License-Identifier: MIT
      pragma solidity ^0.8.17;
      import "@openzeppelin/contracts/access/Ownable.sol";
      import "@openzeppelin/contracts/security/ReentrancyGuard.sol";
      import "@openzeppelin/contracts/token/ERC721/IERC721Receiver.sol";
      import "@openzeppelin/contracts/utils/cryptography/MerkleProof.sol";
      import "@openzeppelin/contracts/utils/Address.sol";
      import "./interfaces/INishikigoi.sol";
      contract Minter is Ownable, IERC721Receiver, ReentrancyGuard {
          INishikigoi public nishikigoiNFTContract;
          address public cushionAddress;
          address private agentAddress;
          uint256 public constant PUBLIC_PRICE = 0.03 ether;    
          uint256 public constant ALLOWLIST_PRICE = 0.025 ether;    
          uint256 public constant HOLDER_PRICE = 0.01 ether;
          uint256 public constant PRICE = 0.03 ether;
          
          bool public isPublicSaleActive;
          bool public isAllowlistSaleActive;
          bool public isHolderSaleActive;
          bytes32 public allowlistMerkleRoot;
          bytes32 public holderMerkleRoot;
          /// @dev Holder Address => Minted token amount
          mapping (address => uint256) public holderMinted;
          /// @dev TokenId => Seed
          mapping (uint256 => bytes32) private tokenIdToSeed;
          enum Artist { Okazz, Raf, Ykxotkx }
          event Minted(uint256 indexed _tokenId, Artist indexed _artist, bytes32 indexed _seed);
          constructor(
              address _cushionAddress,
              address _targetAddress
          ) {
              nishikigoiNFTContract = INishikigoi(_targetAddress);
              cushionAddress = _cushionAddress;
          }
          function publicMint(
              uint256[] memory _tokenIdList
          ) external payable nonReentrant {
              require(isPublicSaleActive, "Minter: Public sale is not active");
              require(_isValidTokenIdList(_tokenIdList), "Minter: Invalid token id list");
              require(msg.value == PUBLIC_PRICE * _tokenIdList.length, "Minter: Incorrect payment amount");
              _mintNFT(msg.sender, _tokenIdList);
          }
          function publicMintByAgent(
              uint256[] memory _tokenIdList,
              address _recipient
          ) external payable onlyAgent nonReentrant {
              require(isPublicSaleActive, "Minter: Public sale is not active");
              require(_isValidTokenIdList(_tokenIdList), "Minter: Invalid token id list");
              require(msg.value == PUBLIC_PRICE * _tokenIdList.length, "Minter: Incorrect payment amount");
              _mintNFT(_recipient, _tokenIdList);
          }
          function allowlistMint(
              bytes32[] calldata _merkleProof,
              uint256[] memory _tokenIdList
          ) external payable nonReentrant {
              require(isAllowlistSaleActive, "Minter: Allowlist sale is not active");
              require(_isValidTokenIdList(_tokenIdList), "Minter: Invalid token id list");
              require(MerkleProof.verify(_merkleProof, allowlistMerkleRoot,  keccak256(abi.encodePacked(msg.sender))), "Minter: Invalid Merkle Proof");
              require(msg.value == ALLOWLIST_PRICE * _tokenIdList.length, "Minter: Incorrect payment amount");
              _mintNFT(msg.sender, _tokenIdList);
          }
          function allowlistMintByAgent(
              bytes32[] calldata _merkleProof,
              uint256[] memory _tokenIdList,
              address _recipient
          ) external payable onlyAgent nonReentrant {
              require(isAllowlistSaleActive, "Minter: Allowlist sale is not active");
              require(_isValidTokenIdList(_tokenIdList), "Minter: Invalid token id list");
              require(MerkleProof.verify(_merkleProof, allowlistMerkleRoot,  keccak256(abi.encodePacked(_recipient))), "Minter: Invalid Merkle Proof");
              require(msg.value == ALLOWLIST_PRICE * _tokenIdList.length, "Minter: Incorrect payment amount");
              _mintNFT(_recipient, _tokenIdList);
          }
          function holderMint(
              bytes32[] calldata _merkleProof,
              uint256 _quantity,
              uint256[] memory _tokenIdList
          ) external payable nonReentrant {
              require(isHolderSaleActive, "Minter: Holder sale is not active");
              require(holderMinted[msg.sender] + _tokenIdList.length <= _quantity, "Minter: Exceeds the number of mints allowed");
              require(_isValidTokenIdList(_tokenIdList), "Minter: Invalid token id list");
              require(MerkleProof.verify(_merkleProof, holderMerkleRoot,  keccak256(abi.encodePacked(msg.sender, _quantity))), "Minter: Invalid Merkle Proof");
              require(msg.value == HOLDER_PRICE * _tokenIdList.length, "Minter: Incorrect payment amount");
              
              _mintNFT(msg.sender, _tokenIdList);
              holderMinted[msg.sender] += _tokenIdList.length;
          }
          function holderMintByAgent(
              bytes32[] calldata _merkleProof,
              uint256 _quantity,
              uint256[] memory _tokenIdList,
              address _recipient
          ) external payable onlyAgent nonReentrant {
              require(isHolderSaleActive, "Minter: Holder sale is not active");
              require(holderMinted[_recipient] + _tokenIdList.length <= _quantity, "Minter: Exceeds the number of mints allowed");
              require(_isValidTokenIdList(_tokenIdList), "Minter: Invalid token id list");
              require(MerkleProof.verify(_merkleProof, holderMerkleRoot,  keccak256(abi.encodePacked(_recipient, _quantity))), "Minter: Invalid Merkle Proof");
              require(msg.value == HOLDER_PRICE * _tokenIdList.length, "Minter: Incorrect payment amount");
              
              _mintNFT(_recipient, _tokenIdList);
              holderMinted[_recipient] += _tokenIdList.length;
          }
          function ownerMintByMintForPromotion(address _to, uint256 _quantity) external onlyOwner {
              nishikigoiNFTContract.mintForPromotion(_to, _quantity);
          }
          function ownerMint(address _to, uint256[] memory _tokenIdList) external onlyOwner {
              _overrideBuyBundle(_to, _tokenIdList);
          }
          modifier onlyAgent() {
              require(msg.sender == agentAddress, "Minter: Invalid agent address");
              _;
          }
          function _changeSaleState(bool _state) internal {
              nishikigoiNFTContract.updateSaleStatus(_state);
          }
          function _overrideBuyBundle(address _to, uint256[] memory _tokenIdList) internal {
              _changeSaleState(true);
              nishikigoiNFTContract.buyBundle{value: PRICE * _tokenIdList.length}(_tokenIdList);
              _changeSaleState(false);
              for (uint256 i = 0; i < _tokenIdList.length; i++) {
                  _transfer(_to, _tokenIdList[i]);
                  emit Minted(_tokenIdList[i], getArtistFor3rdSale(_tokenIdList[i]), tokenIdToSeed[_tokenIdList[i]]);
              }
          }
          function _transfer(address _to, uint256 tokenId) internal {
              nishikigoiNFTContract.safeTransferFrom(address(this), cushionAddress, tokenId);        
              nishikigoiNFTContract.safeTransferFrom(cushionAddress, _to, tokenId);        
          }
          function _generateSeed(address _addr, uint256[] memory _tokenIdList) internal {
              for (uint256 i = 0; i < _tokenIdList.length; i++) {
                  tokenIdToSeed[_tokenIdList[i]] = keccak256(abi.encodePacked(_tokenIdList[i], block.number, blockhash(block.number - 1), _addr));
              }
          }
          function _mintNFT(address _addr, uint256[] memory _tokenIdList) internal {
              _generateSeed(_addr, _tokenIdList);
              _overrideBuyBundle(_addr, _tokenIdList);
          }
          function _isValidTokenIdList(
              uint256[] memory _tokenIdList
          ) internal pure returns (bool) {
              for (uint256 i = 0; i < _tokenIdList.length; i++) {
                  if (_tokenIdList[i] >= 8666) {
                      return false;
                  }            
              }
              return true;
          }
          function overrideTransferOwnership(address _to) public onlyOwner {
              require(!Address.isContract(_to), "Minter: Cannot transfer ownership to a contract");
              bool anySaleActive = isHolderSaleActive || isAllowlistSaleActive || isPublicSaleActive;
              require(!anySaleActive, "Minter: Sale is active");
              nishikigoiNFTContract.transferOwnership(_to);
          }
          function setIsHolderSaleActive(bool _state) external onlyOwner {
              isHolderSaleActive = _state;
          }
          function setIsAllowlistSaleActive(bool _state) external onlyOwner {
              isAllowlistSaleActive = _state;
          }
          function setIsPublicSaleActive(bool _state) external onlyOwner {
              isPublicSaleActive = _state;
          }
          function setMerkleRoot(
              bytes32 _holderMerkleRoot,
              bytes32 _allowlistMerkleRoot
          ) external onlyOwner {
              holderMerkleRoot = _holderMerkleRoot;
              allowlistMerkleRoot = _allowlistMerkleRoot;
          }
          function setBaseURI(string memory _newBaseURI) external onlyOwner {
              nishikigoiNFTContract.updateBaseURI(_newBaseURI);
          }
          function setAgentAddress(address _agentAddress) external onlyOwner {
              agentAddress = _agentAddress;
          }
          function setCushionAddress(address _cushionAddress) external onlyOwner {
              cushionAddress = _cushionAddress;
          }
          
          function getSeed(uint256 tokenId) external view returns (bytes32) {
              return tokenIdToSeed[tokenId];
          }
          function getArtistFor3rdSale(uint256 tokenId) public pure returns (Artist) {        
              if (tokenId <= 1937) {
                  /// @dev 0
                  return Artist.Okazz;
              } else if (tokenId <= 3854) {
                  /// @dev 1
                  return Artist.Raf;
              } else {
                  /// @dev 2
                  return Artist.Ykxotkx;
              }
          }
          
          function withdraw(address payable _receiptAddress) external onlyOwner {
              require(_receiptAddress != address(0), "Minter: Invalid receipt address");
              _receiptAddress.transfer(address(this).balance);        
              nishikigoiNFTContract.withdrawETH();
          }
          function withdrawOfNishikigoi() external onlyOwner {
              nishikigoiNFTContract.withdrawETH();
          }
          function onERC721Received(address, address, uint256, bytes calldata) external pure override returns (bytes4) {
              return this.onERC721Received.selector;
          }
          receive() external payable {}
      }

      File 2 of 2: Nishikigoi
      //SPDX-License-Identifier: MIT
      pragma solidity 0.8.6;
      import "@openzeppelin/contracts/token/ERC721/ERC721.sol";
      import "@openzeppelin/contracts/security/ReentrancyGuard.sol";
      import "@openzeppelin/contracts/access/Ownable.sol";
      import "@openzeppelin/contracts/utils/Address.sol";
      import "@openzeppelin/contracts/utils/Strings.sol";
      interface iNishikigoi {
          function remainingAmountForPromotion() external view returns (uint256);
          function remainingAmountForSale() external view returns (uint256);
          function isOnSale() external view returns (bool);
          function mintedSalesTokenIdList(
              uint256 offset,
              uint256 limit
          ) external view returns (uint256[] memory);
          function buy(uint256 tokenId) external payable;
          function buyBundle(uint256[] memory tokenIdList) external payable;
          // functions for admin
          function updateSaleStatus(bool _isOnSale) external;
          function updateBaseURI(string calldata newBaseURI) external;
          function freezeMetadata() external;
          function mintForPromotion(
              address to,
              uint256 amount
          ) external;
          function withdrawETH() external;
      }
      contract Nishikigoi is iNishikigoi, ERC721, ReentrancyGuard, Ownable {
          using Strings for uint256;
          uint256 public constant PRICE = 0.03 ether;
          uint256 public constant MAX_SUPPLY = 10000;
          uint256 private _nextReservedTokenId = 9800;
          uint256 private _remainingAmountForPromotion = 200;
          uint256 private _remainingAmountForSale = 9800;
          uint256[] private _mintedTokenIdList;
          address payable private _recipient;
          bool private _isOnSale;
          bool private _isMetadataFroze;
          string private __baseURI;
          constructor(
              string memory baseURI,
              address payable __recipient
          )
          ERC721("Nishikigoi", "KOI")
          {
              require(__recipient != address(0), "Nishikigoi: Invalid address");
              _recipient = __recipient;
              __baseURI = baseURI;
          }
          function remainingAmountForPromotion() external override view returns (uint256) {
              return _remainingAmountForPromotion;
          }
          function remainingAmountForSale() external override view returns (uint256) {
              return _remainingAmountForSale;
          }
          function isOnSale() external view override returns (bool) {
              return _isOnSale;
          }
          function mintedSalesTokenIdList(
              uint256 offset,
              uint256 limit
          ) external override view returns (uint256[] memory) {
              uint256 minted = _mintedTokenIdList.length;
              if (minted == 0) {
                  return _mintedTokenIdList;
              }
              if (minted < offset) {
                  return new uint256[](0);
              }
              uint256 length = limit;
              if (minted < offset + limit) {
                  length = minted - offset;
              }
              uint256[] memory list = new uint256[](length);
              for (uint256 i = offset; i < offset + limit; i++) {
                  if (_mintedTokenIdList.length <= i) {
                      break;
                  }
                  list[i - offset] = _mintedTokenIdList[i];
              }
              return list;
          }
          function _baseURI() internal override view virtual returns (string memory) {
              return __baseURI;
          }
          function tokenURI(uint256 tokenId) public view virtual override returns (string memory) {
              require(_exists(tokenId), "Nishikigoi: URI query for nonexistent token");
              string memory baseURI = _baseURI();
              return bytes(baseURI).length > 0 ? string(abi.encodePacked(baseURI, tokenId.toString(), ".json")) : "";
          }
          function buy(uint256 tokenId) external override nonReentrant payable {
              require(_isOnSale, "Nishikigoi: Not on sale");
              require(msg.value == PRICE, "Nishikigoi: Invalid value");
              require(tokenId < _nextReservedTokenId, "Nishikigoi: Invalid id");
              _mintedTokenIdList.push(tokenId);
              _remainingAmountForSale--;
              _safeMint(_msgSender(), tokenId);
          }
          function buyBundle(uint256[] memory tokenIdList) external override nonReentrant payable {
              uint256 count = tokenIdList.length;
              require(_isOnSale, "Nishikigoi: Not on sale");
              require(msg.value == PRICE * count, "Nishikigoi: Invalid value");
              _remainingAmountForSale -= count;
              for (uint256 i; i < count; i++) {
                  require(tokenIdList[i] < _nextReservedTokenId, "Nishikigoi: Invalid id");
                  _mintedTokenIdList.push(tokenIdList[i]);
                  _safeMint(_msgSender(), tokenIdList[i]);
              }
          }
          function updateSaleStatus(bool __isOnSale) external override onlyOwner {
              _isOnSale = __isOnSale;
          }
          function updateBaseURI(string calldata newBaseURI) external override onlyOwner {
              require(!_isMetadataFroze, "Nishikigoi: Metadata is froze");
              __baseURI = newBaseURI;
          }
          function freezeMetadata() external override onlyOwner {
              require(!_isMetadataFroze, "Nishikigoi: Already froze");
              _isMetadataFroze = true;
          }
          function mintForPromotion(
              address to,
              uint256 amount
          ) external override onlyOwner {
              _remainingAmountForPromotion -= amount;
              for (uint256 i = _nextReservedTokenId; i < _nextReservedTokenId + amount; i++) {
                  _safeMint(to, i);
              }
              _nextReservedTokenId += amount;
          }
          function withdrawETH() external override onlyOwner {
              Address.sendValue(_recipient, address(this).balance);
          }
      }
      // SPDX-License-Identifier: MIT
      pragma solidity ^0.8.0;
      import "./IERC721.sol";
      import "./IERC721Receiver.sol";
      import "./extensions/IERC721Metadata.sol";
      import "../../utils/Address.sol";
      import "../../utils/Context.sol";
      import "../../utils/Strings.sol";
      import "../../utils/introspection/ERC165.sol";
      /**
       * @dev Implementation of https://eips.ethereum.org/EIPS/eip-721[ERC721] Non-Fungible Token Standard, including
       * the Metadata extension, but not including the Enumerable extension, which is available separately as
       * {ERC721Enumerable}.
       */
      contract ERC721 is Context, ERC165, IERC721, IERC721Metadata {
          using Address for address;
          using Strings for uint256;
          // Token name
          string private _name;
          // Token symbol
          string private _symbol;
          // Mapping from token ID to owner address
          mapping(uint256 => address) private _owners;
          // Mapping owner address to token count
          mapping(address => uint256) private _balances;
          // Mapping from token ID to approved address
          mapping(uint256 => address) private _tokenApprovals;
          // Mapping from owner to operator approvals
          mapping(address => mapping(address => bool)) private _operatorApprovals;
          /**
           * @dev Initializes the contract by setting a `name` and a `symbol` to the token collection.
           */
          constructor(string memory name_, string memory symbol_) {
              _name = name_;
              _symbol = symbol_;
          }
          /**
           * @dev See {IERC165-supportsInterface}.
           */
          function supportsInterface(bytes4 interfaceId) public view virtual override(ERC165, IERC165) returns (bool) {
              return
                  interfaceId == type(IERC721).interfaceId ||
                  interfaceId == type(IERC721Metadata).interfaceId ||
                  super.supportsInterface(interfaceId);
          }
          /**
           * @dev See {IERC721-balanceOf}.
           */
          function balanceOf(address owner) public view virtual override returns (uint256) {
              require(owner != address(0), "ERC721: balance query for the zero address");
              return _balances[owner];
          }
          /**
           * @dev See {IERC721-ownerOf}.
           */
          function ownerOf(uint256 tokenId) public view virtual override returns (address) {
              address owner = _owners[tokenId];
              require(owner != address(0), "ERC721: owner query for nonexistent token");
              return owner;
          }
          /**
           * @dev See {IERC721Metadata-name}.
           */
          function name() public view virtual override returns (string memory) {
              return _name;
          }
          /**
           * @dev See {IERC721Metadata-symbol}.
           */
          function symbol() public view virtual override returns (string memory) {
              return _symbol;
          }
          /**
           * @dev See {IERC721Metadata-tokenURI}.
           */
          function tokenURI(uint256 tokenId) public view virtual override returns (string memory) {
              require(_exists(tokenId), "ERC721Metadata: URI query for nonexistent token");
              string memory baseURI = _baseURI();
              return bytes(baseURI).length > 0 ? string(abi.encodePacked(baseURI, tokenId.toString())) : "";
          }
          /**
           * @dev Base URI for computing {tokenURI}. If set, the resulting URI for each
           * token will be the concatenation of the `baseURI` and the `tokenId`. Empty
           * by default, can be overriden in child contracts.
           */
          function _baseURI() internal view virtual returns (string memory) {
              return "";
          }
          /**
           * @dev See {IERC721-approve}.
           */
          function approve(address to, uint256 tokenId) public virtual override {
              address owner = ERC721.ownerOf(tokenId);
              require(to != owner, "ERC721: approval to current owner");
              require(
                  _msgSender() == owner || isApprovedForAll(owner, _msgSender()),
                  "ERC721: approve caller is not owner nor approved for all"
              );
              _approve(to, tokenId);
          }
          /**
           * @dev See {IERC721-getApproved}.
           */
          function getApproved(uint256 tokenId) public view virtual override returns (address) {
              require(_exists(tokenId), "ERC721: approved query for nonexistent token");
              return _tokenApprovals[tokenId];
          }
          /**
           * @dev See {IERC721-setApprovalForAll}.
           */
          function setApprovalForAll(address operator, bool approved) public virtual override {
              require(operator != _msgSender(), "ERC721: approve to caller");
              _operatorApprovals[_msgSender()][operator] = approved;
              emit ApprovalForAll(_msgSender(), operator, approved);
          }
          /**
           * @dev See {IERC721-isApprovedForAll}.
           */
          function isApprovedForAll(address owner, address operator) public view virtual override returns (bool) {
              return _operatorApprovals[owner][operator];
          }
          /**
           * @dev See {IERC721-transferFrom}.
           */
          function transferFrom(
              address from,
              address to,
              uint256 tokenId
          ) public virtual override {
              //solhint-disable-next-line max-line-length
              require(_isApprovedOrOwner(_msgSender(), tokenId), "ERC721: transfer caller is not owner nor approved");
              _transfer(from, to, tokenId);
          }
          /**
           * @dev See {IERC721-safeTransferFrom}.
           */
          function safeTransferFrom(
              address from,
              address to,
              uint256 tokenId
          ) public virtual override {
              safeTransferFrom(from, to, tokenId, "");
          }
          /**
           * @dev See {IERC721-safeTransferFrom}.
           */
          function safeTransferFrom(
              address from,
              address to,
              uint256 tokenId,
              bytes memory _data
          ) public virtual override {
              require(_isApprovedOrOwner(_msgSender(), tokenId), "ERC721: transfer caller is not owner nor approved");
              _safeTransfer(from, to, tokenId, _data);
          }
          /**
           * @dev Safely transfers `tokenId` token from `from` to `to`, checking first that contract recipients
           * are aware of the ERC721 protocol to prevent tokens from being forever locked.
           *
           * `_data` is additional data, it has no specified format and it is sent in call to `to`.
           *
           * This internal function is equivalent to {safeTransferFrom}, and can be used to e.g.
           * implement alternative mechanisms to perform token transfer, such as signature-based.
           *
           * Requirements:
           *
           * - `from` cannot be the zero address.
           * - `to` cannot be the zero address.
           * - `tokenId` token must exist and be owned by `from`.
           * - If `to` refers to a smart contract, it must implement {IERC721Receiver-onERC721Received}, which is called upon a safe transfer.
           *
           * Emits a {Transfer} event.
           */
          function _safeTransfer(
              address from,
              address to,
              uint256 tokenId,
              bytes memory _data
          ) internal virtual {
              _transfer(from, to, tokenId);
              require(_checkOnERC721Received(from, to, tokenId, _data), "ERC721: transfer to non ERC721Receiver implementer");
          }
          /**
           * @dev Returns whether `tokenId` exists.
           *
           * Tokens can be managed by their owner or approved accounts via {approve} or {setApprovalForAll}.
           *
           * Tokens start existing when they are minted (`_mint`),
           * and stop existing when they are burned (`_burn`).
           */
          function _exists(uint256 tokenId) internal view virtual returns (bool) {
              return _owners[tokenId] != address(0);
          }
          /**
           * @dev Returns whether `spender` is allowed to manage `tokenId`.
           *
           * Requirements:
           *
           * - `tokenId` must exist.
           */
          function _isApprovedOrOwner(address spender, uint256 tokenId) internal view virtual returns (bool) {
              require(_exists(tokenId), "ERC721: operator query for nonexistent token");
              address owner = ERC721.ownerOf(tokenId);
              return (spender == owner || getApproved(tokenId) == spender || isApprovedForAll(owner, spender));
          }
          /**
           * @dev Safely mints `tokenId` and transfers it to `to`.
           *
           * Requirements:
           *
           * - `tokenId` must not exist.
           * - If `to` refers to a smart contract, it must implement {IERC721Receiver-onERC721Received}, which is called upon a safe transfer.
           *
           * Emits a {Transfer} event.
           */
          function _safeMint(address to, uint256 tokenId) internal virtual {
              _safeMint(to, tokenId, "");
          }
          /**
           * @dev Same as {xref-ERC721-_safeMint-address-uint256-}[`_safeMint`], with an additional `data` parameter which is
           * forwarded in {IERC721Receiver-onERC721Received} to contract recipients.
           */
          function _safeMint(
              address to,
              uint256 tokenId,
              bytes memory _data
          ) internal virtual {
              _mint(to, tokenId);
              require(
                  _checkOnERC721Received(address(0), to, tokenId, _data),
                  "ERC721: transfer to non ERC721Receiver implementer"
              );
          }
          /**
           * @dev Mints `tokenId` and transfers it to `to`.
           *
           * WARNING: Usage of this method is discouraged, use {_safeMint} whenever possible
           *
           * Requirements:
           *
           * - `tokenId` must not exist.
           * - `to` cannot be the zero address.
           *
           * Emits a {Transfer} event.
           */
          function _mint(address to, uint256 tokenId) internal virtual {
              require(to != address(0), "ERC721: mint to the zero address");
              require(!_exists(tokenId), "ERC721: token already minted");
              _beforeTokenTransfer(address(0), to, tokenId);
              _balances[to] += 1;
              _owners[tokenId] = to;
              emit Transfer(address(0), to, tokenId);
          }
          /**
           * @dev Destroys `tokenId`.
           * The approval is cleared when the token is burned.
           *
           * Requirements:
           *
           * - `tokenId` must exist.
           *
           * Emits a {Transfer} event.
           */
          function _burn(uint256 tokenId) internal virtual {
              address owner = ERC721.ownerOf(tokenId);
              _beforeTokenTransfer(owner, address(0), tokenId);
              // Clear approvals
              _approve(address(0), tokenId);
              _balances[owner] -= 1;
              delete _owners[tokenId];
              emit Transfer(owner, address(0), tokenId);
          }
          /**
           * @dev Transfers `tokenId` from `from` to `to`.
           *  As opposed to {transferFrom}, this imposes no restrictions on msg.sender.
           *
           * Requirements:
           *
           * - `to` cannot be the zero address.
           * - `tokenId` token must be owned by `from`.
           *
           * Emits a {Transfer} event.
           */
          function _transfer(
              address from,
              address to,
              uint256 tokenId
          ) internal virtual {
              require(ERC721.ownerOf(tokenId) == from, "ERC721: transfer of token that is not own");
              require(to != address(0), "ERC721: transfer to the zero address");
              _beforeTokenTransfer(from, to, tokenId);
              // Clear approvals from the previous owner
              _approve(address(0), tokenId);
              _balances[from] -= 1;
              _balances[to] += 1;
              _owners[tokenId] = to;
              emit Transfer(from, to, tokenId);
          }
          /**
           * @dev Approve `to` to operate on `tokenId`
           *
           * Emits a {Approval} event.
           */
          function _approve(address to, uint256 tokenId) internal virtual {
              _tokenApprovals[tokenId] = to;
              emit Approval(ERC721.ownerOf(tokenId), to, tokenId);
          }
          /**
           * @dev Internal function to invoke {IERC721Receiver-onERC721Received} on a target address.
           * The call is not executed if the target address is not a contract.
           *
           * @param from address representing the previous owner of the given token ID
           * @param to target address that will receive the tokens
           * @param tokenId uint256 ID of the token to be transferred
           * @param _data bytes optional data to send along with the call
           * @return bool whether the call correctly returned the expected magic value
           */
          function _checkOnERC721Received(
              address from,
              address to,
              uint256 tokenId,
              bytes memory _data
          ) private returns (bool) {
              if (to.isContract()) {
                  try IERC721Receiver(to).onERC721Received(_msgSender(), from, tokenId, _data) returns (bytes4 retval) {
                      return retval == IERC721Receiver.onERC721Received.selector;
                  } catch (bytes memory reason) {
                      if (reason.length == 0) {
                          revert("ERC721: transfer to non ERC721Receiver implementer");
                      } else {
                          assembly {
                              revert(add(32, reason), mload(reason))
                          }
                      }
                  }
              } else {
                  return true;
              }
          }
          /**
           * @dev Hook that is called before any token transfer. This includes minting
           * and burning.
           *
           * Calling conditions:
           *
           * - When `from` and `to` are both non-zero, ``from``'s `tokenId` will be
           * transferred to `to`.
           * - When `from` is zero, `tokenId` will be minted for `to`.
           * - When `to` is zero, ``from``'s `tokenId` 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 tokenId
          ) internal virtual {}
      }
      // SPDX-License-Identifier: MIT
      pragma solidity ^0.8.0;
      /**
       * @dev Contract module that helps prevent reentrant calls to a function.
       *
       * Inheriting from `ReentrancyGuard` will make the {nonReentrant} modifier
       * available, which can be applied to functions to make sure there are no nested
       * (reentrant) calls to them.
       *
       * Note that because there is a single `nonReentrant` guard, functions marked as
       * `nonReentrant` may not call one another. This can be worked around by making
       * those functions `private`, and then adding `external` `nonReentrant` entry
       * points to them.
       *
       * TIP: If you would like to learn more about reentrancy and alternative ways
       * to protect against it, check out our blog post
       * https://blog.openzeppelin.com/reentrancy-after-istanbul/[Reentrancy After Istanbul].
       */
      abstract contract ReentrancyGuard {
          // Booleans are more expensive than uint256 or any type that takes up a full
          // word because each write operation emits an extra SLOAD to first read the
          // slot's contents, replace the bits taken up by the boolean, and then write
          // back. This is the compiler's defense against contract upgrades and
          // pointer aliasing, and it cannot be disabled.
          // The values being non-zero value makes deployment a bit more expensive,
          // but in exchange the refund on every call to nonReentrant will be lower in
          // amount. Since refunds are capped to a percentage of the total
          // transaction's gas, it is best to keep them low in cases like this one, to
          // increase the likelihood of the full refund coming into effect.
          uint256 private constant _NOT_ENTERED = 1;
          uint256 private constant _ENTERED = 2;
          uint256 private _status;
          constructor() {
              _status = _NOT_ENTERED;
          }
          /**
           * @dev Prevents a contract from calling itself, directly or indirectly.
           * Calling a `nonReentrant` function from another `nonReentrant`
           * function is not supported. It is possible to prevent this from happening
           * by making the `nonReentrant` function external, and make it call a
           * `private` function that does the actual work.
           */
          modifier nonReentrant() {
              // On the first call to nonReentrant, _notEntered will be true
              require(_status != _ENTERED, "ReentrancyGuard: reentrant call");
              // Any calls to nonReentrant after this point will fail
              _status = _ENTERED;
              _;
              // By storing the original value once again, a refund is triggered (see
              // https://eips.ethereum.org/EIPS/eip-2200)
              _status = _NOT_ENTERED;
          }
      }
      // SPDX-License-Identifier: MIT
      pragma solidity ^0.8.0;
      import "../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.
       *
       * By default, the owner account will be the one that deploys the contract. 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;
          event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);
          /**
           * @dev Initializes the contract setting the deployer as the initial owner.
           */
          constructor() {
              _setOwner(_msgSender());
          }
          /**
           * @dev Returns the address of the current owner.
           */
          function owner() public view virtual returns (address) {
              return _owner;
          }
          /**
           * @dev Throws if called by any account other than the owner.
           */
          modifier onlyOwner() {
              require(owner() == _msgSender(), "Ownable: caller is not the owner");
              _;
          }
          /**
           * @dev Leaves the contract without owner. It will not be possible to call
           * `onlyOwner` functions anymore. Can only be called by the current owner.
           *
           * NOTE: Renouncing ownership will leave the contract without an owner,
           * thereby removing any functionality that is only available to the owner.
           */
          function renounceOwnership() public virtual onlyOwner {
              _setOwner(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 {
              require(newOwner != address(0), "Ownable: new owner is the zero address");
              _setOwner(newOwner);
          }
          function _setOwner(address newOwner) private {
              address oldOwner = _owner;
              _owner = newOwner;
              emit OwnershipTransferred(oldOwner, newOwner);
          }
      }
      // SPDX-License-Identifier: MIT
      pragma solidity ^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;
              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");
              (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");
              (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");
              (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");
              (bool success, bytes memory returndata) = target.delegatecall(data);
              return verifyCallResult(success, returndata, errorMessage);
          }
          /**
           * @dev Tool to verifies that a low level call was successful, and revert if it wasn't, either by bubbling the
           * revert reason using the provided one.
           *
           * _Available since v4.3._
           */
          function verifyCallResult(
              bool success,
              bytes memory returndata,
              string memory errorMessage
          ) internal 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
                      assembly {
                          let returndata_size := mload(returndata)
                          revert(add(32, returndata), returndata_size)
                      }
                  } else {
                      revert(errorMessage);
                  }
              }
          }
      }
      // SPDX-License-Identifier: MIT
      pragma solidity ^0.8.0;
      /**
       * @dev String operations.
       */
      library Strings {
          bytes16 private constant _HEX_SYMBOLS = "0123456789abcdef";
          /**
           * @dev Converts a `uint256` to its ASCII `string` decimal representation.
           */
          function toString(uint256 value) internal pure returns (string memory) {
              // Inspired by OraclizeAPI's implementation - MIT licence
              // https://github.com/oraclize/ethereum-api/blob/b42146b063c7d6ee1358846c198246239e9360e8/oraclizeAPI_0.4.25.sol
              if (value == 0) {
                  return "0";
              }
              uint256 temp = value;
              uint256 digits;
              while (temp != 0) {
                  digits++;
                  temp /= 10;
              }
              bytes memory buffer = new bytes(digits);
              while (value != 0) {
                  digits -= 1;
                  buffer[digits] = bytes1(uint8(48 + uint256(value % 10)));
                  value /= 10;
              }
              return string(buffer);
          }
          /**
           * @dev Converts a `uint256` to its ASCII `string` hexadecimal representation.
           */
          function toHexString(uint256 value) internal pure returns (string memory) {
              if (value == 0) {
                  return "0x00";
              }
              uint256 temp = value;
              uint256 length = 0;
              while (temp != 0) {
                  length++;
                  temp >>= 8;
              }
              return toHexString(value, length);
          }
          /**
           * @dev Converts a `uint256` to its ASCII `string` hexadecimal representation with fixed length.
           */
          function toHexString(uint256 value, uint256 length) internal pure returns (string memory) {
              bytes memory buffer = new bytes(2 * length + 2);
              buffer[0] = "0";
              buffer[1] = "x";
              for (uint256 i = 2 * length + 1; i > 1; --i) {
                  buffer[i] = _HEX_SYMBOLS[value & 0xf];
                  value >>= 4;
              }
              require(value == 0, "Strings: hex length insufficient");
              return string(buffer);
          }
      }
      // SPDX-License-Identifier: MIT
      pragma solidity ^0.8.0;
      import "../../utils/introspection/IERC165.sol";
      /**
       * @dev Required interface of an ERC721 compliant contract.
       */
      interface IERC721 is IERC165 {
          /**
           * @dev Emitted when `tokenId` token is transferred from `from` to `to`.
           */
          event Transfer(address indexed from, address indexed to, uint256 indexed tokenId);
          /**
           * @dev Emitted when `owner` enables `approved` to manage the `tokenId` token.
           */
          event Approval(address indexed owner, address indexed approved, uint256 indexed tokenId);
          /**
           * @dev Emitted when `owner` enables or disables (`approved`) `operator` to manage all of its assets.
           */
          event ApprovalForAll(address indexed owner, address indexed operator, bool approved);
          /**
           * @dev Returns the number of tokens in ``owner``'s account.
           */
          function balanceOf(address owner) external view returns (uint256 balance);
          /**
           * @dev Returns the owner of the `tokenId` token.
           *
           * Requirements:
           *
           * - `tokenId` must exist.
           */
          function ownerOf(uint256 tokenId) external view returns (address owner);
          /**
           * @dev Safely transfers `tokenId` token from `from` to `to`, checking first that contract recipients
           * are aware of the ERC721 protocol to prevent tokens from being forever locked.
           *
           * Requirements:
           *
           * - `from` cannot be the zero address.
           * - `to` cannot be the zero address.
           * - `tokenId` token must exist and be owned by `from`.
           * - If the caller is not `from`, it must be have been allowed to move this token by either {approve} or {setApprovalForAll}.
           * - If `to` refers to a smart contract, it must implement {IERC721Receiver-onERC721Received}, which is called upon a safe transfer.
           *
           * Emits a {Transfer} event.
           */
          function safeTransferFrom(
              address from,
              address to,
              uint256 tokenId
          ) external;
          /**
           * @dev Transfers `tokenId` token from `from` to `to`.
           *
           * WARNING: Usage of this method is discouraged, use {safeTransferFrom} whenever possible.
           *
           * Requirements:
           *
           * - `from` cannot be the zero address.
           * - `to` cannot be the zero address.
           * - `tokenId` token must be owned by `from`.
           * - If the caller is not `from`, it must be approved to move this token by either {approve} or {setApprovalForAll}.
           *
           * Emits a {Transfer} event.
           */
          function transferFrom(
              address from,
              address to,
              uint256 tokenId
          ) external;
          /**
           * @dev Gives permission to `to` to transfer `tokenId` token to another account.
           * The approval is cleared when the token is transferred.
           *
           * Only a single account can be approved at a time, so approving the zero address clears previous approvals.
           *
           * Requirements:
           *
           * - The caller must own the token or be an approved operator.
           * - `tokenId` must exist.
           *
           * Emits an {Approval} event.
           */
          function approve(address to, uint256 tokenId) external;
          /**
           * @dev Returns the account approved for `tokenId` token.
           *
           * Requirements:
           *
           * - `tokenId` must exist.
           */
          function getApproved(uint256 tokenId) external view returns (address operator);
          /**
           * @dev Approve or remove `operator` as an operator for the caller.
           * Operators can call {transferFrom} or {safeTransferFrom} for any token owned by the caller.
           *
           * Requirements:
           *
           * - The `operator` cannot be the caller.
           *
           * Emits an {ApprovalForAll} event.
           */
          function setApprovalForAll(address operator, bool _approved) external;
          /**
           * @dev Returns if the `operator` is allowed to manage all of the assets of `owner`.
           *
           * See {setApprovalForAll}
           */
          function isApprovedForAll(address owner, address operator) external view returns (bool);
          /**
           * @dev Safely transfers `tokenId` token from `from` to `to`.
           *
           * Requirements:
           *
           * - `from` cannot be the zero address.
           * - `to` cannot be the zero address.
           * - `tokenId` token must exist and be owned by `from`.
           * - If the caller is not `from`, it must be approved to move this token by either {approve} or {setApprovalForAll}.
           * - If `to` refers to a smart contract, it must implement {IERC721Receiver-onERC721Received}, which is called upon a safe transfer.
           *
           * Emits a {Transfer} event.
           */
          function safeTransferFrom(
              address from,
              address to,
              uint256 tokenId,
              bytes calldata data
          ) external;
      }
      // SPDX-License-Identifier: MIT
      pragma solidity ^0.8.0;
      /**
       * @title ERC721 token receiver interface
       * @dev Interface for any contract that wants to support safeTransfers
       * from ERC721 asset contracts.
       */
      interface IERC721Receiver {
          /**
           * @dev Whenever an {IERC721} `tokenId` token is transferred to this contract via {IERC721-safeTransferFrom}
           * by `operator` from `from`, this function is called.
           *
           * It must return its Solidity selector to confirm the token transfer.
           * If any other value is returned or the interface is not implemented by the recipient, the transfer will be reverted.
           *
           * The selector can be obtained in Solidity with `IERC721.onERC721Received.selector`.
           */
          function onERC721Received(
              address operator,
              address from,
              uint256 tokenId,
              bytes calldata data
          ) external returns (bytes4);
      }
      // SPDX-License-Identifier: MIT
      pragma solidity ^0.8.0;
      import "../IERC721.sol";
      /**
       * @title ERC-721 Non-Fungible Token Standard, optional metadata extension
       * @dev See https://eips.ethereum.org/EIPS/eip-721
       */
      interface IERC721Metadata is IERC721 {
          /**
           * @dev Returns the token collection name.
           */
          function name() external view returns (string memory);
          /**
           * @dev Returns the token collection symbol.
           */
          function symbol() external view returns (string memory);
          /**
           * @dev Returns the Uniform Resource Identifier (URI) for `tokenId` token.
           */
          function tokenURI(uint256 tokenId) external view returns (string memory);
      }
      // SPDX-License-Identifier: MIT
      pragma solidity ^0.8.0;
      /**
       * @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;
          }
      }
      // SPDX-License-Identifier: MIT
      pragma solidity ^0.8.0;
      import "./IERC165.sol";
      /**
       * @dev Implementation of the {IERC165} interface.
       *
       * Contracts that want to implement ERC165 should inherit from this contract and override {supportsInterface} to check
       * for the additional interface id that will be supported. For example:
       *
       * ```solidity
       * function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) {
       *     return interfaceId == type(MyInterface).interfaceId || super.supportsInterface(interfaceId);
       * }
       * ```
       *
       * Alternatively, {ERC165Storage} provides an easier to use but more expensive implementation.
       */
      abstract contract ERC165 is IERC165 {
          /**
           * @dev See {IERC165-supportsInterface}.
           */
          function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) {
              return interfaceId == type(IERC165).interfaceId;
          }
      }
      // SPDX-License-Identifier: MIT
      pragma solidity ^0.8.0;
      /**
       * @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);
      }