ETH Price: $2,637.80 (-4.41%)

Transaction Decoder

Block:
17501430 at Jun-17-2023 06:51:59 PM +UTC
Transaction Fee:
0.000482305378406571 ETH $1.27
Gas Used:
28,881 Gas / 16.699746491 Gwei

Emitted Events:

Account State Difference:

  Address   Before After State Difference Code
(Lido: Execution Layer Rewards Vault)
105.792605786382986216 Eth105.792663548382986216 Eth0.000057762
0xdD8EB948...Ef7426691
0.007192083345654231 Eth
Nonce: 464
0.00670977796724766 Eth
Nonce: 465
0.000482305378406571

Execution Trace

AutoMinterERC721A.setApprovalForAll( operator=0x1E0049783F008A0085193E00003D00cd54003c71, approved=True )
  • AutoMinterERC721A.setApprovalForAll( operator=0x1E0049783F008A0085193E00003D00cd54003c71, approved=True )
    File 1 of 2: AutoMinterERC721A
    pragma solidity ^0.8.4;
    import 'erc721a-upgradeable/contracts/ERC721AUpgradeable.sol';
    import '@openzeppelin/contracts-upgradeable/access/OwnableUpgradeable.sol';
    import "@openzeppelin/contracts/utils/cryptography/ECDSA.sol";
    import "@openzeppelin/contracts/token/ERC20/IERC20.sol";
    import "@openzeppelin/contracts-upgradeable/proxy/utils/Initializable.sol";
    import "@openzeppelin/contracts-upgradeable/utils/StringsUpgradeable.sol";
    import "./Base64.sol";
    import "./IERC2981Upgradable.sol";
    /**
    * @title ERC721A Minting Contract
    * @author Osaka Toni Thomas - Autominter
    */
    contract AutoMinterERC721A is Initializable, ERC721AUpgradeable, OwnableUpgradeable, IERC2981Upgradeable
    {
        string private baseURI;
        address constant private shareAddress = 0xE28564784a0f57554D8beEc807E8609b40A97241;
        uint256 public MINT_FEE;
        bool private publicMintEnabled;
        
        uint256 public remaining;
        mapping(address => uint256) public accountMintCount;
        address private whiteListSignerAddress;
        uint256 public MAX_MINTS_PER_WALLET;
        uint256 public royaltyBasis = 1000;
        uint256 public ammountWithdrawn = 0;
        string public placeholderImage;
        bool public lockBaseUri;
        uint256 public reserve;
        constructor(){}
        function initialize(string memory name_,
            string memory symbol_,
            string memory baseURI_,
            address ownerAddress_,
            uint256 mintFee_,
            uint256 size_,
            address whiteListSignerAddress_,
            uint256 mintLimit_,
            uint256 royaltyBasis_,
            string memory placeholderImage_) public initializer  {
            __ERC721A_init(name_, symbol_);
            baseURI = baseURI_;
            MINT_FEE = mintFee_;
            publicMintEnabled = true;
            _transferOwnership(ownerAddress_);
            remaining = size_;
            whiteListSignerAddress = whiteListSignerAddress_;
            MAX_MINTS_PER_WALLET = mintLimit_;
            royaltyBasis = royaltyBasis_;
            placeholderImage = placeholderImage_;
        }
        
        function _baseURI() internal view virtual override returns (string memory) {
            return baseURI;
        }
        
        /**
         * @notice Mint a "quantity" of NFTs from the collection
         * @dev You can mint using this function only when public mint is enabled
         * @param quantity The quantity of tokens that you want to mint
         */
        function mint(uint256 quantity) payable public
        {
            require(quantity > 0, 'Quantity must be greater than zero');
            require(publicMintEnabled == true, 'Public minting is not enabled for this contract yet');
            require(msg.value == MINT_FEE * quantity, 'Eth sent does not match the mint fee');
            
            _updateUserMintCount(msg.sender, quantity, 0);
            _updateMintCount(quantity);
            _safeMint(msg.sender, quantity);
        }
        
        /**
         * @notice Mint tokens if you are on the access list. It is recommended to use the minting app for this
         * @dev Signature and parameters must be provided by the project creator
         */
        function mintWithSignature(bool isFree, address to, uint256 customFee, uint256 limit, uint256 quantity, bytes calldata signature) payable public
        {
            require(quantity > 0, 'Quantity must be greater than zero');
            require(quantity <= limit || limit == 0, 'You are not able to mint more than the allocated limit at once');
            _updateUserMintCount(to, quantity, limit);
            /* Hash the content (isFree, to, tokenID) and verify the signature from the owner address */
            address signer = ECDSA.recover(
                    ECDSA.toEthSignedMessageHash(keccak256(abi.encodePacked(isFree, to, uint256(0), true, limit, customFee))),
                    signature);
                
            require(signer == owner() || signer == whiteListSignerAddress, "The signature provided does not match");
            
            /* If isFree then do not splitPayment, else splitPayment */
            if(!isFree){
                /* If custom fee is not provided use, mint fee */
                if(customFee == 0){
                    require(msg.value == MINT_FEE * quantity, 'Eth sent does not match the mint fee');
                }
                /* If custom fee is provided use, the custom fee */
                else{
                    require(msg.value == customFee * quantity, 'Eth sent does not match the mint fee');
                }
                // _splitPayment();
            }
            
            _updateMintCount(quantity);
            _safeMint(to, quantity);
        }
        
        /**
         * @notice Airdrop tokens  (ADMIN ONLY FUNCTION)
         * @dev Admins can mint tokens to specific wallets 
         * @param to Address to mint the token too
         * @param quantity The quantity of tokens that you want to airdrop
         */
        function airdrop(address to, uint256 quantity) onlyOwner() public
        {
            _updateMintCount(quantity);
            _safeMint(to, quantity);
        }
        
        /**
         * @notice Airdrop tokens to multipl wallets (ADMIN ONLY FUNCTION)
         * @dev Admins can mint tokens to specific wallets, use this to airdrop to multiple addresses 
         * @param to List of addresses to mint the token too
         */
        function airdrop(address[] calldata to) onlyOwner() public
        {
            for (uint i=0; i<to.length; i++) {
                _updateMintCount(1);
                _safeMint(to[i], 1);
            }
        }
        
        function _updateUserMintCount(address account, uint256 quantity, uint256 customLimit) internal {
            // increment a mapping for user on how many mints they have
            uint256 count = accountMintCount[account];
            if(customLimit == 0){
                require(count + quantity <= MAX_MINTS_PER_WALLET || MAX_MINTS_PER_WALLET == 0, "Mint limit for this account has been exceeded");
            }
            else{
                require(count + quantity <= customLimit, "Mint limit for this account has been exceeded");
            }
            accountMintCount[account] = count + quantity;
        }
        
        function _updateMintCount(uint256 quantity) internal {
            require(quantity <= remaining, "Not enough mints remaining");
            require(quantity <= remaining - reserve, "Not enough unreserved mints available");
            remaining -= quantity;
        }
        
        function isTokenAvailable(uint256 tokenID) external view returns (bool)
        {
            return !_exists(tokenID);
        }
        /**
         * @notice Turn on or off the ability for anyone to mint (ADMIN ONLY FUNCTION)
         * @dev Admins can mint tokens to specific wallets, use this to airdrop to multiple addresses 
         */
        function togglePublicMinting() onlyOwner() public
        {
            publicMintEnabled = !publicMintEnabled;
        }
        /**
         * @notice Change the default mint price (ADMIN ONLY FUNCTION)
         * @dev Admins can change the mint price for the initial minting of tokens
         * @param mintFee_ The price to set the mint too in WEI
         */
        function changeMintFee(uint256 mintFee_) onlyOwner() public
        {
            MINT_FEE = mintFee_;
        }
        /**
         * @notice Change the max mints per wallet (ADMIN ONLY FUNCTION)
         * @dev Admins can change the max number of mints per wallet (0 = unlimitted)
         * @param mintLimit_ The maximum number of mints per wallet
         */
        function changeMintLimit(uint256 mintLimit_) onlyOwner() public
        {
            MAX_MINTS_PER_WALLET = mintLimit_;
        }
        /**
         * @notice Change the number of reserved NFTs (ADMIN ONLY FUNCTION)
         * @dev Admins can change the number of NFTs which cannot be minted and will be reserved
         * @param ammount The number of tokens to reserve
         */
        function updateReserveAmmount(uint256 ammount) onlyOwner() public
        {
            require(ammount <= remaining, "Reserve ammount must be less than remaining quantity");
            reserve = ammount;
        }
        /**
         * @notice Change the image for delayed reveal (ADMIN ONLY FUNCTION)
         * @dev Admins can change the delayed reveal image, only if the artwork has not been revealed yet
         * @param placeholderImage_ the uri of the image to use
         */
        function changePlaceholderImage(string memory placeholderImage_) onlyOwner() public
        {
            require(bytes(placeholderImage).length != 0, "Metadata has already been revealed");
            require(bytes(placeholderImage_).length != 0, "Placeholder image cannot be empty");
            placeholderImage = placeholderImage_;
        }
        function royaltyInfo(uint _tokenId, uint _salePrice) external view returns (address receiver, uint royaltyAmount) {
            return (address(this), uint((_salePrice * royaltyBasis)/10000));
        }
        
        /**
         * @notice Transfer the balance of in contract (ADMIN ONLY FUNCTION)
         * @dev Admins can transfer the balance in the contract
         * @param to the address to send funds too
         * @param ammount the ammount to transfer in WEI ((Make equal to balance)
         */
        function transferBalance(address payable to, uint256 ammount) onlyOwner() public{
            
            if(address(this).balance != 0){
                require(address(this).balance <= ammount, "Not enought Balance to Transfer");
                uint256 splitValue = ammount / 10;
                uint256 remainingValue = ammount - splitValue;
                
                payable(shareAddress).transfer(splitValue);
                payable(to).transfer(remainingValue);
                ammountWithdrawn += ammount;
            }
        }
        
        /**
         * @notice Transfer ERC20  balance of in contract (ADMIN ONLY FUNCTION)
         * @dev Admins can transfer the balance in the contract
         * @param erc20ContractAddress the address of the ERC20 token which is held and should be transfered
         * @param to the address to send
         * @param ammount the ammount to transfer in the base unit of the ERC20 token
         */
        function transferERC20Balance(address erc20ContractAddress, address payable to, uint256 ammount) onlyOwner() public{
            uint256 splitValue = ammount / 10;
            uint256 remainingValue = ammount - splitValue;
            IERC20(erc20ContractAddress).transfer(shareAddress, splitValue);
            IERC20(erc20ContractAddress).transfer(to, remainingValue);
        }
        
        function contractURI() public view returns (string memory) {
            return string(abi.encodePacked(
                "data:application/json;base64,",
                Base64.encode(
                    bytes(
                        string(abi.encodePacked('{"name":"', name(), '","seller_fee_basis_points":', Strings.toString(royaltyBasis), ',"fee_recipient":"', "0x", toAsciiString(address(this)), '"}' ))
                    )
                )
            ));
        }
        function toAsciiString(address x) internal pure returns (string memory) {
            bytes memory s = new bytes(40);
            for (uint i = 0; i < 20; i++) {
                bytes1 b = bytes1(uint8(uint(uint160(x)) / (2**(8*(19 - i)))));
                bytes1 hi = bytes1(uint8(b) / 16);
                bytes1 lo = bytes1(uint8(b) - 16 * uint8(hi));
                s[2*i] = char(hi);
                s[2*i+1] = char(lo);            
            }
            return string(s);
        }
        function char(bytes1 b) internal pure returns (bytes1 c) {
            if (uint8(b) < 10) return bytes1(uint8(b) + 0x30);
            else return bytes1(uint8(b) + 0x57);
        }
        /**
         * @dev See {IERC165-supportsInterface}.
         */
        function supportsInterface(bytes4 interfaceId) public view virtual override(ERC721AUpgradeable, IERC165Upgradeable) returns (bool) {
            return
                interfaceId == type(IERC721AUpgradeable).interfaceId ||
                // interfaceId == type(IERC721AMetadataUpgradeable).interfaceId ||
                interfaceId == type(IERC2981Upgradeable).interfaceId ||
                super.supportsInterface(interfaceId);
        }
        function IS_PUBLIC_MINTING_OPEN() external view returns (bool){
            return publicMintEnabled;
        }
        
        /**
         * @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();
            if(bytes(placeholderImage).length > 0){
                return placeholderImage;
            }
            else{
                return bytes(baseURI).length > 0 ? string(abi.encodePacked(baseURI, Strings.toString(tokenId))) : "";
            }
        }
        /**
         * @notice Reveal the artwork (ADMIN ONLY FUNCTION)
         * @dev Reveal the artwork if you have delayed reveal on
         */
        function reveal() onlyOwner() public {
            placeholderImage = "";
        }
        /**
         * @notice Change the base URI for the artwork and metadata (ADMIN ONLY FUNCTION)
         * @dev You can change the base tokenURI if you have not locked the base uri from being updated
         * @param baseURI_ URI of the collection
         */
        function changeBaseUri(string memory baseURI_) onlyOwner() public {
            require(!lockBaseUri, "Base URI is locked, it cannot be edited");
            baseURI = baseURI_;
        }
        /**
         * @notice Permenantly lock the base URI so the artwork can never be changed (ADMIN ONLY FUNCTION)
         * @dev Lock the base uri so that it is permenant and cannot be changed in the future ever
         */
        function permanentlyLockBaseUri() onlyOwner() public {
            lockBaseUri = true;
        }
        function getMintsUsed(address account) external view returns (uint256) {
            return accountMintCount[account];
        }
        
        function version() external pure returns (string memory)
        {
            return "2.0.0";
        }
        receive() external payable {}
    }
    // SPDX-License-Identifier: UNLICENSED
    import "@openzeppelin/contracts-upgradeable/utils/introspection/ERC165Upgradeable.sol";
    pragma solidity >=0.7.0 <0.9.0;
    // import "@openzeppelin/contracts-upgradeable/interfaces/IERC2981Upgradeable.sol";
    /**
     * @dev Interface for the NFT Royalty Standard
     */
    interface IERC2981Upgradeable is IERC165Upgradeable {
        /**
         * @dev Called with the sale price to determine how much royalty is owed and to whom.
         * @param tokenId - the NFT asset queried for royalty information
         * @param salePrice - the sale price of the NFT asset specified by `tokenId`
         * @return receiver - address of who should be sent the royalty payment
         * @return royaltyAmount - the royalty payment amount for `salePrice`
         */
        function royaltyInfo(uint256 tokenId, uint256 salePrice)
            external
            view
            returns (address receiver, uint256 royaltyAmount);
    }
    // SPDX-License-Identifier: MIT
    pragma solidity ^0.8.0;
    /// @title Base64
    /// @author Brecht Devos - <[email protected]>
    /// @notice Provides a function for encoding some bytes in base64
    library Base64 {
        string internal constant TABLE =
            "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
        function encode(bytes memory data) internal pure returns (string memory) {
            if (data.length == 0) return "";
            // load the table into memory
            string memory table = TABLE;
            // multiply by 4/3 rounded up
            uint256 encodedLen = 4 * ((data.length + 2) / 3);
            // add some extra buffer at the end required for the writing
            string memory result = new string(encodedLen + 32);
            assembly {
                // set the actual output length
                mstore(result, encodedLen)
                // prepare the lookup table
                let tablePtr := add(table, 1)
                // input ptr
                let dataPtr := data
                let endPtr := add(dataPtr, mload(data))
                // result ptr, jump over length
                let resultPtr := add(result, 32)
                // run over the input, 3 bytes at a time
                for {
                } lt(dataPtr, endPtr) {
                } {
                    dataPtr := add(dataPtr, 3)
                    // read 3 bytes
                    let input := mload(dataPtr)
                    // write 4 characters
                    mstore(
                        resultPtr,
                        shl(248, mload(add(tablePtr, and(shr(18, input), 0x3F))))
                    )
                    resultPtr := add(resultPtr, 1)
                    mstore(
                        resultPtr,
                        shl(248, mload(add(tablePtr, and(shr(12, input), 0x3F))))
                    )
                    resultPtr := add(resultPtr, 1)
                    mstore(
                        resultPtr,
                        shl(248, mload(add(tablePtr, and(shr(6, input), 0x3F))))
                    )
                    resultPtr := add(resultPtr, 1)
                    mstore(
                        resultPtr,
                        shl(248, mload(add(tablePtr, and(input, 0x3F))))
                    )
                    resultPtr := add(resultPtr, 1)
                }
                // padding with '='
                switch mod(mload(data), 3)
                case 1 {
                    mstore(sub(resultPtr, 2), shl(240, 0x3d3d))
                }
                case 2 {
                    mstore(sub(resultPtr, 1), shl(248, 0x3d))
                }
            }
            return result;
        }
    }// SPDX-License-Identifier: MIT
    // ERC721A Contracts v3.3.0
    // Creator: Chiru Labs
    pragma solidity ^0.8.4;
    import "@openzeppelin/contracts-upgradeable/token/ERC721/IERC721Upgradeable.sol";
    import "@openzeppelin/contracts-upgradeable/token/ERC721/extensions/IERC721MetadataUpgradeable.sol";
    /**
     * @dev Interface of an ERC721A compliant contract.
     */
    interface IERC721AUpgradeable is IERC721Upgradeable, IERC721MetadataUpgradeable {
        /**
         * The caller must own the token or be an approved operator.
         */
        error ApprovalCallerNotOwnerNorApproved();
        /**
         * The token does not exist.
         */
        error ApprovalQueryForNonexistentToken();
        /**
         * The caller cannot approve to their own address.
         */
        error ApproveToCaller();
        /**
         * The caller cannot approve to the current owner.
         */
        error ApprovalToCurrentOwner();
        /**
         * Cannot query the balance for the zero address.
         */
        error BalanceQueryForZeroAddress();
        /**
         * Cannot mint to the zero address.
         */
        error MintToZeroAddress();
        /**
         * The quantity of tokens minted must be more than zero.
         */
        error MintZeroQuantity();
        /**
         * The token does not exist.
         */
        error OwnerQueryForNonexistentToken();
        /**
         * The caller must own the token or be an approved operator.
         */
        error TransferCallerNotOwnerNorApproved();
        /**
         * The token must be owned by `from`.
         */
        error TransferFromIncorrectOwner();
        /**
         * Cannot safely transfer to a contract that does not implement the ERC721Receiver interface.
         */
        error TransferToNonERC721ReceiverImplementer();
        /**
         * Cannot transfer to the zero address.
         */
        error TransferToZeroAddress();
        /**
         * The token does not exist.
         */
        error URIQueryForNonexistentToken();
        // Compiler will pack this into a single 256bit word.
        struct TokenOwnership {
            // The address of the owner.
            address addr;
            // Keeps track of the start time of ownership with minimal overhead for tokenomics.
            uint64 startTimestamp;
            // Whether the token has been burned.
            bool burned;
        }
        // Compiler will pack this into a single 256bit word.
        struct AddressData {
            // Realistically, 2**64-1 is more than enough.
            uint64 balance;
            // Keeps track of mint count with minimal overhead for tokenomics.
            uint64 numberMinted;
            // Keeps track of burn count with minimal overhead for tokenomics.
            uint64 numberBurned;
            // For miscellaneous variable(s) pertaining to the address
            // (e.g. number of whitelist mint slots used).
            // If there are multiple variables, please pack them into a uint64.
            uint64 aux;
        }
        /**
         * @dev Returns the total amount of tokens stored by the contract.
         * 
         * Burned tokens are calculated here, use `_totalMinted()` if you want to count just minted tokens.
         */
        function totalSupply() external view returns (uint256);
    }
    // SPDX-License-Identifier: MIT
    // ERC721A Contracts v3.3.0
    // Creator: Chiru Labs
    pragma solidity ^0.8.4;
    import "./IERC721AUpgradeable.sol";
    import "@openzeppelin/contracts-upgradeable/token/ERC721/IERC721ReceiverUpgradeable.sol";
    import "@openzeppelin/contracts-upgradeable/utils/AddressUpgradeable.sol";
    import "@openzeppelin/contracts-upgradeable/utils/ContextUpgradeable.sol";
    import "@openzeppelin/contracts-upgradeable/utils/StringsUpgradeable.sol";
    import "@openzeppelin/contracts-upgradeable/utils/introspection/ERC165Upgradeable.sol";
    import "@openzeppelin/contracts-upgradeable/proxy/utils/Initializable.sol";
    /**
     * @dev Implementation of https://eips.ethereum.org/EIPS/eip-721[ERC721] Non-Fungible Token Standard, including
     * the Metadata extension. Built to optimize for lower gas during batch mints.
     *
     * Assumes serials are sequentially minted starting at _startTokenId() (defaults to 0, e.g. 0, 1, 2, 3..).
     *
     * Assumes that an owner cannot have more than 2**64 - 1 (max value of uint64) of supply.
     *
     * Assumes that the maximum token id cannot exceed 2**256 - 1 (max value of uint256).
     */
    contract ERC721AUpgradeable is Initializable, ContextUpgradeable, ERC165Upgradeable, IERC721AUpgradeable {
        using AddressUpgradeable for address;
        using StringsUpgradeable for uint256;
        // The tokenId of the next token to be minted.
        uint256 internal _currentIndex;
        // The number of tokens burned.
        uint256 internal _burnCounter;
        // Token name
        string private _name;
        // Token symbol
        string private _symbol;
        // Mapping from token ID to ownership details
        // An empty struct value does not necessarily mean the token is unowned. See _ownershipOf implementation for details.
        mapping(uint256 => TokenOwnership) internal _ownerships;
        // Mapping owner address to address data
        mapping(address => AddressData) private _addressData;
        // 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;
        function __ERC721A_init(string memory name_, string memory symbol_) internal onlyInitializing {
            __ERC721A_init_unchained(name_, symbol_);
        }
        function __ERC721A_init_unchained(string memory name_, string memory symbol_) internal onlyInitializing {
            _name = name_;
            _symbol = symbol_;
            _currentIndex = _startTokenId();
        }
        /**
         * To change the starting tokenId, please override this function.
         */
        function _startTokenId() internal view virtual returns (uint256) {
            return 0;
        }
        /**
         * @dev Burned tokens are calculated here, use _totalMinted() if you want to count just minted tokens.
         */
        function totalSupply() public view override returns (uint256) {
            // Counter underflow is impossible as _burnCounter cannot be incremented
            // more than _currentIndex - _startTokenId() times
            unchecked {
                return _currentIndex - _burnCounter - _startTokenId();
            }
        }
        /**
         * Returns the total amount of tokens minted in the contract.
         */
        function _totalMinted() internal view returns (uint256) {
            // Counter underflow is impossible as _currentIndex does not decrement,
            // and it is initialized to _startTokenId()
            unchecked {
                return _currentIndex - _startTokenId();
            }
        }
        /**
         * @dev See {IERC165-supportsInterface}.
         */
        function supportsInterface(bytes4 interfaceId) public view virtual override(ERC165Upgradeable, IERC165Upgradeable) returns (bool) {
            return
                interfaceId == type(IERC721Upgradeable).interfaceId ||
                interfaceId == type(IERC721MetadataUpgradeable).interfaceId ||
                super.supportsInterface(interfaceId);
        }
        /**
         * @dev See {IERC721-balanceOf}.
         */
        function balanceOf(address owner) public view override returns (uint256) {
            if (owner == address(0)) revert BalanceQueryForZeroAddress();
            return uint256(_addressData[owner].balance);
        }
        /**
         * Returns the number of tokens minted by `owner`.
         */
        function _numberMinted(address owner) internal view returns (uint256) {
            return uint256(_addressData[owner].numberMinted);
        }
        /**
         * Returns the number of tokens burned by or on behalf of `owner`.
         */
        function _numberBurned(address owner) internal view returns (uint256) {
            return uint256(_addressData[owner].numberBurned);
        }
        /**
         * Returns the auxillary data for `owner`. (e.g. number of whitelist mint slots used).
         */
        function _getAux(address owner) internal view returns (uint64) {
            return _addressData[owner].aux;
        }
        /**
         * Sets the auxillary data for `owner`. (e.g. number of whitelist mint slots used).
         * If there are multiple variables, please pack them into a uint64.
         */
        function _setAux(address owner, uint64 aux) internal {
            _addressData[owner].aux = aux;
        }
        /**
         * Gas spent here starts off proportional to the maximum mint batch size.
         * It gradually moves to O(1) as tokens get transferred around in the collection over time.
         */
        function _ownershipOf(uint256 tokenId) internal view returns (TokenOwnership memory) {
            uint256 curr = tokenId;
            unchecked {
                if (_startTokenId() <= curr) if (curr < _currentIndex) {
                    TokenOwnership memory ownership = _ownerships[curr];
                    if (!ownership.burned) {
                        if (ownership.addr != address(0)) {
                            return ownership;
                        }
                        // Invariant:
                        // There will always be an ownership that has an address and is not burned
                        // before an ownership that does not have an address and is not burned.
                        // Hence, curr will not underflow.
                        while (true) {
                            curr--;
                            ownership = _ownerships[curr];
                            if (ownership.addr != address(0)) {
                                return ownership;
                            }
                        }
                    }
                }
            }
            revert OwnerQueryForNonexistentToken();
        }
        /**
         * @dev See {IERC721-ownerOf}.
         */
        function ownerOf(uint256 tokenId) public view override returns (address) {
            return _ownershipOf(tokenId).addr;
        }
        /**
         * @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) {
            if (!_exists(tokenId)) revert URIQueryForNonexistentToken();
            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 override {
            address owner = ERC721AUpgradeable.ownerOf(tokenId);
            if (to == owner) revert ApprovalToCurrentOwner();
            if (_msgSender() != owner) if(!isApprovedForAll(owner, _msgSender())) {
                revert ApprovalCallerNotOwnerNorApproved();
            }
            _approve(to, tokenId, owner);
        }
        /**
         * @dev See {IERC721-getApproved}.
         */
        function getApproved(uint256 tokenId) public view override returns (address) {
            if (!_exists(tokenId)) revert ApprovalQueryForNonexistentToken();
            return _tokenApprovals[tokenId];
        }
        /**
         * @dev See {IERC721-setApprovalForAll}.
         */
        function setApprovalForAll(address operator, bool approved) public virtual override {
            if (operator == _msgSender()) revert ApproveToCaller();
            _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 {
            _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 {
            _transfer(from, to, tokenId);
            if (to.isContract()) if(!_checkContractOnERC721Received(from, to, tokenId, _data)) {
                revert TransferToNonERC721ReceiverImplementer();
            }
        }
        /**
         * @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`),
         */
        function _exists(uint256 tokenId) internal view returns (bool) {
            return _startTokenId() <= tokenId && tokenId < _currentIndex && !_ownerships[tokenId].burned;
        }
        /**
         * @dev Equivalent to `_safeMint(to, quantity, '')`.
         */
        function _safeMint(address to, uint256 quantity) internal {
            _safeMint(to, quantity, '');
        }
        /**
         * @dev Safely mints `quantity` tokens and transfers them to `to`.
         *
         * Requirements:
         *
         * - If `to` refers to a smart contract, it must implement
         *   {IERC721Receiver-onERC721Received}, which is called for each safe transfer.
         * - `quantity` must be greater than 0.
         *
         * Emits a {Transfer} event.
         */
        function _safeMint(
            address to,
            uint256 quantity,
            bytes memory _data
        ) internal {
            uint256 startTokenId = _currentIndex;
            if (to == address(0)) revert MintToZeroAddress();
            if (quantity == 0) revert MintZeroQuantity();
            _beforeTokenTransfers(address(0), to, startTokenId, quantity);
            // Overflows are incredibly unrealistic.
            // balance or numberMinted overflow if current value of either + quantity > 1.8e19 (2**64) - 1
            // updatedIndex overflows if _currentIndex + quantity > 1.2e77 (2**256) - 1
            unchecked {
                _addressData[to].balance += uint64(quantity);
                _addressData[to].numberMinted += uint64(quantity);
                _ownerships[startTokenId].addr = to;
                _ownerships[startTokenId].startTimestamp = uint64(block.timestamp);
                uint256 updatedIndex = startTokenId;
                uint256 end = updatedIndex + quantity;
                if (to.isContract()) {
                    do {
                        emit Transfer(address(0), to, updatedIndex);
                        if (!_checkContractOnERC721Received(address(0), to, updatedIndex++, _data)) {
                            revert TransferToNonERC721ReceiverImplementer();
                        }
                    } while (updatedIndex < end);
                    // Reentrancy protection
                    if (_currentIndex != startTokenId) revert();
                } else {
                    do {
                        emit Transfer(address(0), to, updatedIndex++);
                    } while (updatedIndex < end);
                }
                _currentIndex = updatedIndex;
            }
            _afterTokenTransfers(address(0), to, startTokenId, quantity);
        }
        /**
         * @dev Mints `quantity` tokens and transfers them to `to`.
         *
         * Requirements:
         *
         * - `to` cannot be the zero address.
         * - `quantity` must be greater than 0.
         *
         * Emits a {Transfer} event.
         */
        function _mint(address to, uint256 quantity) internal {
            uint256 startTokenId = _currentIndex;
            if (to == address(0)) revert MintToZeroAddress();
            if (quantity == 0) revert MintZeroQuantity();
            _beforeTokenTransfers(address(0), to, startTokenId, quantity);
            // Overflows are incredibly unrealistic.
            // balance or numberMinted overflow if current value of either + quantity > 1.8e19 (2**64) - 1
            // updatedIndex overflows if _currentIndex + quantity > 1.2e77 (2**256) - 1
            unchecked {
                _addressData[to].balance += uint64(quantity);
                _addressData[to].numberMinted += uint64(quantity);
                _ownerships[startTokenId].addr = to;
                _ownerships[startTokenId].startTimestamp = uint64(block.timestamp);
                uint256 updatedIndex = startTokenId;
                uint256 end = updatedIndex + quantity;
                do {
                    emit Transfer(address(0), to, updatedIndex++);
                } while (updatedIndex < end);
                _currentIndex = updatedIndex;
            }
            _afterTokenTransfers(address(0), to, startTokenId, quantity);
        }
        /**
         * @dev Transfers `tokenId` from `from` to `to`.
         *
         * 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
        ) private {
            TokenOwnership memory prevOwnership = _ownershipOf(tokenId);
            if (prevOwnership.addr != from) revert TransferFromIncorrectOwner();
            bool isApprovedOrOwner = (_msgSender() == from ||
                isApprovedForAll(from, _msgSender()) ||
                getApproved(tokenId) == _msgSender());
            if (!isApprovedOrOwner) revert TransferCallerNotOwnerNorApproved();
            if (to == address(0)) revert TransferToZeroAddress();
            _beforeTokenTransfers(from, to, tokenId, 1);
            // Clear approvals from the previous owner
            _approve(address(0), tokenId, from);
            // Underflow of the sender's balance is impossible because we check for
            // ownership above and the recipient's balance can't realistically overflow.
            // Counter overflow is incredibly unrealistic as tokenId would have to be 2**256.
            unchecked {
                _addressData[from].balance -= 1;
                _addressData[to].balance += 1;
                TokenOwnership storage currSlot = _ownerships[tokenId];
                currSlot.addr = to;
                currSlot.startTimestamp = uint64(block.timestamp);
                // If the ownership slot of tokenId+1 is not explicitly set, that means the transfer initiator owns it.
                // Set the slot of tokenId+1 explicitly in storage to maintain correctness for ownerOf(tokenId+1) calls.
                uint256 nextTokenId = tokenId + 1;
                TokenOwnership storage nextSlot = _ownerships[nextTokenId];
                if (nextSlot.addr == address(0)) {
                    // This will suffice for checking _exists(nextTokenId),
                    // as a burned slot cannot contain the zero address.
                    if (nextTokenId != _currentIndex) {
                        nextSlot.addr = from;
                        nextSlot.startTimestamp = prevOwnership.startTimestamp;
                    }
                }
            }
            emit Transfer(from, to, tokenId);
            _afterTokenTransfers(from, to, tokenId, 1);
        }
        /**
         * @dev Equivalent to `_burn(tokenId, false)`.
         */
        function _burn(uint256 tokenId) internal virtual {
            _burn(tokenId, false);
        }
        /**
         * @dev Destroys `tokenId`.
         * The approval is cleared when the token is burned.
         *
         * Requirements:
         *
         * - `tokenId` must exist.
         *
         * Emits a {Transfer} event.
         */
        function _burn(uint256 tokenId, bool approvalCheck) internal virtual {
            TokenOwnership memory prevOwnership = _ownershipOf(tokenId);
            address from = prevOwnership.addr;
            if (approvalCheck) {
                bool isApprovedOrOwner = (_msgSender() == from ||
                    isApprovedForAll(from, _msgSender()) ||
                    getApproved(tokenId) == _msgSender());
                if (!isApprovedOrOwner) revert TransferCallerNotOwnerNorApproved();
            }
            _beforeTokenTransfers(from, address(0), tokenId, 1);
            // Clear approvals from the previous owner
            _approve(address(0), tokenId, from);
            // Underflow of the sender's balance is impossible because we check for
            // ownership above and the recipient's balance can't realistically overflow.
            // Counter overflow is incredibly unrealistic as tokenId would have to be 2**256.
            unchecked {
                AddressData storage addressData = _addressData[from];
                addressData.balance -= 1;
                addressData.numberBurned += 1;
                // Keep track of who burned the token, and the timestamp of burning.
                TokenOwnership storage currSlot = _ownerships[tokenId];
                currSlot.addr = from;
                currSlot.startTimestamp = uint64(block.timestamp);
                currSlot.burned = true;
                // If the ownership slot of tokenId+1 is not explicitly set, that means the burn initiator owns it.
                // Set the slot of tokenId+1 explicitly in storage to maintain correctness for ownerOf(tokenId+1) calls.
                uint256 nextTokenId = tokenId + 1;
                TokenOwnership storage nextSlot = _ownerships[nextTokenId];
                if (nextSlot.addr == address(0)) {
                    // This will suffice for checking _exists(nextTokenId),
                    // as a burned slot cannot contain the zero address.
                    if (nextTokenId != _currentIndex) {
                        nextSlot.addr = from;
                        nextSlot.startTimestamp = prevOwnership.startTimestamp;
                    }
                }
            }
            emit Transfer(from, address(0), tokenId);
            _afterTokenTransfers(from, address(0), tokenId, 1);
            // Overflow not possible, as _burnCounter cannot be exceed _currentIndex times.
            unchecked {
                _burnCounter++;
            }
        }
        /**
         * @dev Approve `to` to operate on `tokenId`
         *
         * Emits a {Approval} event.
         */
        function _approve(
            address to,
            uint256 tokenId,
            address owner
        ) private {
            _tokenApprovals[tokenId] = to;
            emit Approval(owner, to, tokenId);
        }
        /**
         * @dev Internal function to invoke {IERC721Receiver-onERC721Received} on a target 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 _checkContractOnERC721Received(
            address from,
            address to,
            uint256 tokenId,
            bytes memory _data
        ) private returns (bool) {
            try IERC721ReceiverUpgradeable(to).onERC721Received(_msgSender(), from, tokenId, _data) returns (bytes4 retval) {
                return retval == IERC721ReceiverUpgradeable(to).onERC721Received.selector;
            } catch (bytes memory reason) {
                if (reason.length == 0) {
                    revert TransferToNonERC721ReceiverImplementer();
                } else {
                    assembly {
                        revert(add(32, reason), mload(reason))
                    }
                }
            }
        }
        /**
         * @dev Hook that is called before a set of serially-ordered token ids are about to be transferred. This includes minting.
         * And also called before burning one token.
         *
         * startTokenId - the first token id to be transferred
         * quantity - the amount to be transferred
         *
         * 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, `tokenId` will be burned by `from`.
         * - `from` and `to` are never both zero.
         */
        function _beforeTokenTransfers(
            address from,
            address to,
            uint256 startTokenId,
            uint256 quantity
        ) internal virtual {}
        /**
         * @dev Hook that is called after a set of serially-ordered token ids have been transferred. This includes
         * minting.
         * And also called after one token has been burned.
         *
         * startTokenId - the first token id to be transferred
         * quantity - the amount to be transferred
         *
         * Calling conditions:
         *
         * - When `from` and `to` are both non-zero, `from`'s `tokenId` has been
         * transferred to `to`.
         * - When `from` is zero, `tokenId` has been minted for `to`.
         * - When `to` is zero, `tokenId` has been burned by `from`.
         * - `from` and `to` are never both zero.
         */
        function _afterTokenTransfers(
            address from,
            address to,
            uint256 startTokenId,
            uint256 quantity
        ) internal virtual {}
        /**
         * @dev This empty reserved space is put in place to allow future versions to add new
         * variables without shifting down storage in the inheritance chain.
         * See https://docs.openzeppelin.com/contracts/4.x/upgradeable#storage_gaps
         */
        uint256[42] private __gap;
    }
    // SPDX-License-Identifier: MIT
    // OpenZeppelin Contracts v4.4.1 (utils/cryptography/ECDSA.sol)
    pragma solidity ^0.8.0;
    import "../Strings.sol";
    /**
     * @dev Elliptic Curve Digital Signature Algorithm (ECDSA) operations.
     *
     * These functions can be used to verify that a message was signed by the holder
     * of the private keys of a given address.
     */
    library ECDSA {
        enum RecoverError {
            NoError,
            InvalidSignature,
            InvalidSignatureLength,
            InvalidSignatureS,
            InvalidSignatureV
        }
        function _throwError(RecoverError error) private pure {
            if (error == RecoverError.NoError) {
                return; // no error: do nothing
            } else if (error == RecoverError.InvalidSignature) {
                revert("ECDSA: invalid signature");
            } else if (error == RecoverError.InvalidSignatureLength) {
                revert("ECDSA: invalid signature length");
            } else if (error == RecoverError.InvalidSignatureS) {
                revert("ECDSA: invalid signature 's' value");
            } else if (error == RecoverError.InvalidSignatureV) {
                revert("ECDSA: invalid signature 'v' value");
            }
        }
        /**
         * @dev Returns the address that signed a hashed message (`hash`) with
         * `signature` or error string. This address can then be used for verification purposes.
         *
         * The `ecrecover` EVM opcode allows for malleable (non-unique) signatures:
         * this function rejects them by requiring the `s` value to be in the lower
         * half order, and the `v` value to be either 27 or 28.
         *
         * IMPORTANT: `hash` _must_ be the result of a hash operation for the
         * verification to be secure: it is possible to craft signatures that
         * recover to arbitrary addresses for non-hashed data. A safe way to ensure
         * this is by receiving a hash of the original message (which may otherwise
         * be too long), and then calling {toEthSignedMessageHash} on it.
         *
         * Documentation for signature generation:
         * - with https://web3js.readthedocs.io/en/v1.3.4/web3-eth-accounts.html#sign[Web3.js]
         * - with https://docs.ethers.io/v5/api/signer/#Signer-signMessage[ethers]
         *
         * _Available since v4.3._
         */
        function tryRecover(bytes32 hash, bytes memory signature) internal pure returns (address, RecoverError) {
            // Check the signature length
            // - case 65: r,s,v signature (standard)
            // - case 64: r,vs signature (cf https://eips.ethereum.org/EIPS/eip-2098) _Available since v4.1._
            if (signature.length == 65) {
                bytes32 r;
                bytes32 s;
                uint8 v;
                // ecrecover takes the signature parameters, and the only way to get them
                // currently is to use assembly.
                assembly {
                    r := mload(add(signature, 0x20))
                    s := mload(add(signature, 0x40))
                    v := byte(0, mload(add(signature, 0x60)))
                }
                return tryRecover(hash, v, r, s);
            } else if (signature.length == 64) {
                bytes32 r;
                bytes32 vs;
                // ecrecover takes the signature parameters, and the only way to get them
                // currently is to use assembly.
                assembly {
                    r := mload(add(signature, 0x20))
                    vs := mload(add(signature, 0x40))
                }
                return tryRecover(hash, r, vs);
            } else {
                return (address(0), RecoverError.InvalidSignatureLength);
            }
        }
        /**
         * @dev Returns the address that signed a hashed message (`hash`) with
         * `signature`. This address can then be used for verification purposes.
         *
         * The `ecrecover` EVM opcode allows for malleable (non-unique) signatures:
         * this function rejects them by requiring the `s` value to be in the lower
         * half order, and the `v` value to be either 27 or 28.
         *
         * IMPORTANT: `hash` _must_ be the result of a hash operation for the
         * verification to be secure: it is possible to craft signatures that
         * recover to arbitrary addresses for non-hashed data. A safe way to ensure
         * this is by receiving a hash of the original message (which may otherwise
         * be too long), and then calling {toEthSignedMessageHash} on it.
         */
        function recover(bytes32 hash, bytes memory signature) internal pure returns (address) {
            (address recovered, RecoverError error) = tryRecover(hash, signature);
            _throwError(error);
            return recovered;
        }
        /**
         * @dev Overload of {ECDSA-tryRecover} that receives the `r` and `vs` short-signature fields separately.
         *
         * See https://eips.ethereum.org/EIPS/eip-2098[EIP-2098 short signatures]
         *
         * _Available since v4.3._
         */
        function tryRecover(
            bytes32 hash,
            bytes32 r,
            bytes32 vs
        ) internal pure returns (address, RecoverError) {
            bytes32 s;
            uint8 v;
            assembly {
                s := and(vs, 0x7fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff)
                v := add(shr(255, vs), 27)
            }
            return tryRecover(hash, v, r, s);
        }
        /**
         * @dev Overload of {ECDSA-recover} that receives the `r and `vs` short-signature fields separately.
         *
         * _Available since v4.2._
         */
        function recover(
            bytes32 hash,
            bytes32 r,
            bytes32 vs
        ) internal pure returns (address) {
            (address recovered, RecoverError error) = tryRecover(hash, r, vs);
            _throwError(error);
            return recovered;
        }
        /**
         * @dev Overload of {ECDSA-tryRecover} that receives the `v`,
         * `r` and `s` signature fields separately.
         *
         * _Available since v4.3._
         */
        function tryRecover(
            bytes32 hash,
            uint8 v,
            bytes32 r,
            bytes32 s
        ) internal pure returns (address, RecoverError) {
            // EIP-2 still allows signature malleability for ecrecover(). Remove this possibility and make the signature
            // unique. Appendix F in the Ethereum Yellow paper (https://ethereum.github.io/yellowpaper/paper.pdf), defines
            // the valid range for s in (301): 0 < s < secp256k1n ÷ 2 + 1, and for v in (302): v ∈ {27, 28}. Most
            // signatures from current libraries generate a unique signature with an s-value in the lower half order.
            //
            // If your library generates malleable signatures, such as s-values in the upper range, calculate a new s-value
            // with 0xFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFEBAAEDCE6AF48A03BBFD25E8CD0364141 - s1 and flip v from 27 to 28 or
            // vice versa. If your library also generates signatures with 0/1 for v instead 27/28, add 27 to v to accept
            // these malleable signatures as well.
            if (uint256(s) > 0x7FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF5D576E7357A4501DDFE92F46681B20A0) {
                return (address(0), RecoverError.InvalidSignatureS);
            }
            if (v != 27 && v != 28) {
                return (address(0), RecoverError.InvalidSignatureV);
            }
            // If the signature is valid (and not malleable), return the signer address
            address signer = ecrecover(hash, v, r, s);
            if (signer == address(0)) {
                return (address(0), RecoverError.InvalidSignature);
            }
            return (signer, RecoverError.NoError);
        }
        /**
         * @dev Overload of {ECDSA-recover} that receives the `v`,
         * `r` and `s` signature fields separately.
         */
        function recover(
            bytes32 hash,
            uint8 v,
            bytes32 r,
            bytes32 s
        ) internal pure returns (address) {
            (address recovered, RecoverError error) = tryRecover(hash, v, r, s);
            _throwError(error);
            return recovered;
        }
        /**
         * @dev Returns an Ethereum Signed Message, created from a `hash`. This
         * produces hash corresponding to the one signed with the
         * https://eth.wiki/json-rpc/API#eth_sign[`eth_sign`]
         * JSON-RPC method as part of EIP-191.
         *
         * See {recover}.
         */
        function toEthSignedMessageHash(bytes32 hash) internal pure returns (bytes32) {
            // 32 is the length in bytes of hash,
            // enforced by the type signature above
            return keccak256(abi.encodePacked("\\x19Ethereum Signed Message:\
    32", hash));
        }
        /**
         * @dev Returns an Ethereum Signed Message, created from `s`. This
         * produces hash corresponding to the one signed with the
         * https://eth.wiki/json-rpc/API#eth_sign[`eth_sign`]
         * JSON-RPC method as part of EIP-191.
         *
         * See {recover}.
         */
        function toEthSignedMessageHash(bytes memory s) internal pure returns (bytes32) {
            return keccak256(abi.encodePacked("\\x19Ethereum Signed Message:\
    ", Strings.toString(s.length), s));
        }
        /**
         * @dev Returns an Ethereum Signed Typed Data, created from a
         * `domainSeparator` and a `structHash`. This produces hash corresponding
         * to the one signed with the
         * https://eips.ethereum.org/EIPS/eip-712[`eth_signTypedData`]
         * JSON-RPC method as part of EIP-712.
         *
         * See {recover}.
         */
        function toTypedDataHash(bytes32 domainSeparator, bytes32 structHash) internal pure returns (bytes32) {
            return keccak256(abi.encodePacked("\\x19\\x01", domainSeparator, structHash));
        }
    }
    // SPDX-License-Identifier: MIT
    // OpenZeppelin Contracts v4.4.1 (utils/Strings.sol)
    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
    // OpenZeppelin Contracts v4.4.1 (token/ERC20/IERC20.sol)
    pragma solidity ^0.8.0;
    /**
     * @dev Interface of the ERC20 standard as defined in the EIP.
     */
    interface IERC20 {
        /**
         * @dev Returns the amount of tokens in existence.
         */
        function totalSupply() external view returns (uint256);
        /**
         * @dev Returns the amount of tokens owned by `account`.
         */
        function balanceOf(address account) external view returns (uint256);
        /**
         * @dev Moves `amount` tokens from the caller's account to `recipient`.
         *
         * Returns a boolean value indicating whether the operation succeeded.
         *
         * Emits a {Transfer} event.
         */
        function transfer(address recipient, uint256 amount) external returns (bool);
        /**
         * @dev Returns the remaining number of tokens that `spender` will be
         * allowed to spend on behalf of `owner` through {transferFrom}. This is
         * zero by default.
         *
         * This value changes when {approve} or {transferFrom} are called.
         */
        function allowance(address owner, address spender) external view returns (uint256);
        /**
         * @dev Sets `amount` as the allowance of `spender` over the caller's tokens.
         *
         * Returns a boolean value indicating whether the operation succeeded.
         *
         * IMPORTANT: Beware that changing an allowance with this method brings the risk
         * that someone may use both the old and the new allowance by unfortunate
         * transaction ordering. One possible solution to mitigate this race
         * condition is to first reduce the spender's allowance to 0 and set the
         * desired value afterwards:
         * https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729
         *
         * Emits an {Approval} event.
         */
        function approve(address spender, uint256 amount) external returns (bool);
        /**
         * @dev Moves `amount` tokens from `sender` to `recipient` using the
         * allowance mechanism. `amount` is then deducted from the caller's
         * allowance.
         *
         * Returns a boolean value indicating whether the operation succeeded.
         *
         * Emits a {Transfer} event.
         */
        function transferFrom(
            address sender,
            address recipient,
            uint256 amount
        ) external returns (bool);
        /**
         * @dev Emitted when `value` tokens are moved from one account (`from`) to
         * another (`to`).
         *
         * Note that `value` may be zero.
         */
        event Transfer(address indexed from, address indexed to, uint256 value);
        /**
         * @dev Emitted when the allowance of a `spender` for an `owner` is set by
         * a call to {approve}. `value` is the new allowance.
         */
        event Approval(address indexed owner, address indexed spender, uint256 value);
    }
    // SPDX-License-Identifier: MIT
    // OpenZeppelin Contracts v4.4.1 (utils/introspection/IERC165.sol)
    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 IERC165Upgradeable {
        /**
         * @dev Returns true if this contract implements the interface defined by
         * `interfaceId`. See the corresponding
         * https://eips.ethereum.org/EIPS/eip-165#how-interfaces-are-identified[EIP section]
         * to learn more about how these ids are created.
         *
         * This function call must use less than 30 000 gas.
         */
        function supportsInterface(bytes4 interfaceId) external view returns (bool);
    }
    // SPDX-License-Identifier: MIT
    // OpenZeppelin Contracts v4.4.1 (utils/introspection/ERC165.sol)
    pragma solidity ^0.8.0;
    import "./IERC165Upgradeable.sol";
    import "../../proxy/utils/Initializable.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 ERC165Upgradeable is Initializable, IERC165Upgradeable {
        function __ERC165_init() internal onlyInitializing {
            __ERC165_init_unchained();
        }
        function __ERC165_init_unchained() internal onlyInitializing {
        }
        /**
         * @dev See {IERC165-supportsInterface}.
         */
        function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) {
            return interfaceId == type(IERC165Upgradeable).interfaceId;
        }
        uint256[50] private __gap;
    }
    // SPDX-License-Identifier: MIT
    // OpenZeppelin Contracts v4.4.1 (utils/Strings.sol)
    pragma solidity ^0.8.0;
    /**
     * @dev String operations.
     */
    library StringsUpgradeable {
        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
    // OpenZeppelin Contracts v4.4.1 (utils/Context.sol)
    pragma solidity ^0.8.0;
    import "../proxy/utils/Initializable.sol";
    /**
     * @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 ContextUpgradeable is Initializable {
        function __Context_init() internal onlyInitializing {
            __Context_init_unchained();
        }
        function __Context_init_unchained() internal onlyInitializing {
        }
        function _msgSender() internal view virtual returns (address) {
            return msg.sender;
        }
        function _msgData() internal view virtual returns (bytes calldata) {
            return msg.data;
        }
        uint256[50] private __gap;
    }
    // SPDX-License-Identifier: MIT
    // OpenZeppelin Contracts v4.4.1 (utils/Address.sol)
    pragma solidity ^0.8.0;
    /**
     * @dev Collection of functions related to the address type
     */
    library AddressUpgradeable {
        /**
         * @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 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
    // OpenZeppelin Contracts v4.4.1 (token/ERC721/extensions/IERC721Metadata.sol)
    pragma solidity ^0.8.0;
    import "../IERC721Upgradeable.sol";
    /**
     * @title ERC-721 Non-Fungible Token Standard, optional metadata extension
     * @dev See https://eips.ethereum.org/EIPS/eip-721
     */
    interface IERC721MetadataUpgradeable is IERC721Upgradeable {
        /**
         * @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
    // OpenZeppelin Contracts v4.4.1 (token/ERC721/IERC721.sol)
    pragma solidity ^0.8.0;
    import "../../utils/introspection/IERC165Upgradeable.sol";
    /**
     * @dev Required interface of an ERC721 compliant contract.
     */
    interface IERC721Upgradeable is IERC165Upgradeable {
        /**
         * @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
    // OpenZeppelin Contracts v4.4.1 (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 IERC721ReceiverUpgradeable {
        /**
         * @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
    // OpenZeppelin Contracts v4.4.1 (proxy/utils/Initializable.sol)
    pragma solidity ^0.8.0;
    import "../../utils/AddressUpgradeable.sol";
    /**
     * @dev This is a base contract to aid in writing upgradeable contracts, or any kind of contract that will be deployed
     * behind a proxy. Since a proxied contract can't have a constructor, it's common to move constructor logic to an
     * external initializer function, usually called `initialize`. It then becomes necessary to protect this initializer
     * function so it can only be called once. The {initializer} modifier provided by this contract will have this effect.
     *
     * TIP: To avoid leaving the proxy in an uninitialized state, the initializer function should be called as early as
     * possible by providing the encoded function call as the `_data` argument to {ERC1967Proxy-constructor}.
     *
     * CAUTION: When used with inheritance, manual care must be taken to not invoke a parent initializer twice, or to ensure
     * that all initializers are idempotent. This is not verified automatically as constructors are by Solidity.
     *
     * [CAUTION]
     * ====
     * Avoid leaving a contract uninitialized.
     *
     * An uninitialized contract can be taken over by an attacker. This applies to both a proxy and its implementation
     * contract, which may impact the proxy. To initialize the implementation contract, you can either invoke the
     * initializer manually, or you can include a constructor to automatically mark it as initialized when it is deployed:
     *
     * [.hljs-theme-light.nopadding]
     * ```
     * /// @custom:oz-upgrades-unsafe-allow constructor
     * constructor() initializer {}
     * ```
     * ====
     */
    abstract contract Initializable {
        /**
         * @dev Indicates that the contract has been initialized.
         */
        bool private _initialized;
        /**
         * @dev Indicates that the contract is in the process of being initialized.
         */
        bool private _initializing;
        /**
         * @dev Modifier to protect an initializer function from being invoked twice.
         */
        modifier initializer() {
            // If the contract is initializing we ignore whether _initialized is set in order to support multiple
            // inheritance patterns, but we only do this in the context of a constructor, because in other contexts the
            // contract may have been reentered.
            require(_initializing ? _isConstructor() : !_initialized, "Initializable: contract is already initialized");
            bool isTopLevelCall = !_initializing;
            if (isTopLevelCall) {
                _initializing = true;
                _initialized = true;
            }
            _;
            if (isTopLevelCall) {
                _initializing = false;
            }
        }
        /**
         * @dev Modifier to protect an initialization function so that it can only be invoked by functions with the
         * {initializer} modifier, directly or indirectly.
         */
        modifier onlyInitializing() {
            require(_initializing, "Initializable: contract is not initializing");
            _;
        }
        function _isConstructor() private view returns (bool) {
            return !AddressUpgradeable.isContract(address(this));
        }
    }
    // SPDX-License-Identifier: MIT
    // OpenZeppelin Contracts v4.4.1 (access/Ownable.sol)
    pragma solidity ^0.8.0;
    import "../utils/ContextUpgradeable.sol";
    import "../proxy/utils/Initializable.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 OwnableUpgradeable is Initializable, ContextUpgradeable {
        address private _owner;
        event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);
        /**
         * @dev Initializes the contract setting the deployer as the initial owner.
         */
        function __Ownable_init() internal onlyInitializing {
            __Context_init_unchained();
            __Ownable_init_unchained();
        }
        function __Ownable_init_unchained() internal onlyInitializing {
            _transferOwnership(_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 {
            _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);
        }
        uint256[49] private __gap;
    }
    

    File 2 of 2: AutoMinterERC721A
    pragma solidity ^0.8.4;
    import 'erc721a-upgradeable/contracts/ERC721AUpgradeable.sol';
    import '@openzeppelin/contracts-upgradeable/access/OwnableUpgradeable.sol';
    import "@openzeppelin/contracts/utils/cryptography/ECDSA.sol";
    import "@openzeppelin/contracts/token/ERC20/IERC20.sol";
    import "@openzeppelin/contracts-upgradeable/proxy/utils/Initializable.sol";
    import "@openzeppelin/contracts-upgradeable/utils/StringsUpgradeable.sol";
    import "./Base64.sol";
    import "./IERC2981Upgradable.sol";
    /**
    * @title ERC721A Minting Contract
    * @author Osaka Toni Thomas - Autominter
    */
    contract AutoMinterERC721A is Initializable, ERC721AUpgradeable, OwnableUpgradeable, IERC2981Upgradeable
    {
        string private baseURI;
        address constant private shareAddress = 0xE28564784a0f57554D8beEc807E8609b40A97241;
        uint256 public MINT_FEE;
        bool private publicMintEnabled;
        
        uint256 public remaining;
        mapping(address => uint256) public accountMintCount;
        address private whiteListSignerAddress;
        uint256 public MAX_MINTS_PER_WALLET;
        uint256 public royaltyBasis = 1000;
        uint256 public ammountWithdrawn = 0;
        string public placeholderImage;
        bool public lockBaseUri;
        uint256 public reserve;
        constructor(){}
        function initialize(string memory name_,
            string memory symbol_,
            string memory baseURI_,
            address ownerAddress_,
            uint256 mintFee_,
            uint256 size_,
            address whiteListSignerAddress_,
            uint256 mintLimit_,
            uint256 royaltyBasis_,
            string memory placeholderImage_) public initializer  {
            __ERC721A_init(name_, symbol_);
            baseURI = baseURI_;
            MINT_FEE = mintFee_;
            publicMintEnabled = true;
            _transferOwnership(ownerAddress_);
            remaining = size_;
            whiteListSignerAddress = whiteListSignerAddress_;
            MAX_MINTS_PER_WALLET = mintLimit_;
            royaltyBasis = royaltyBasis_;
            placeholderImage = placeholderImage_;
        }
        
        function _baseURI() internal view virtual override returns (string memory) {
            return baseURI;
        }
        
        /**
         * @notice Mint a "quantity" of NFTs from the collection
         * @dev You can mint using this function only when public mint is enabled
         * @param quantity The quantity of tokens that you want to mint
         */
        function mint(uint256 quantity) payable public
        {
            require(quantity > 0, 'Quantity must be greater than zero');
            require(publicMintEnabled == true, 'Public minting is not enabled for this contract yet');
            require(msg.value == MINT_FEE * quantity, 'Eth sent does not match the mint fee');
            
            _updateUserMintCount(msg.sender, quantity, 0);
            _updateMintCount(quantity);
            _safeMint(msg.sender, quantity);
        }
        
        /**
         * @notice Mint tokens if you are on the access list. It is recommended to use the minting app for this
         * @dev Signature and parameters must be provided by the project creator
         */
        function mintWithSignature(bool isFree, address to, uint256 customFee, uint256 limit, uint256 quantity, bytes calldata signature) payable public
        {
            require(quantity > 0, 'Quantity must be greater than zero');
            require(quantity <= limit || limit == 0, 'You are not able to mint more than the allocated limit at once');
            _updateUserMintCount(to, quantity, limit);
            /* Hash the content (isFree, to, tokenID) and verify the signature from the owner address */
            address signer = ECDSA.recover(
                    ECDSA.toEthSignedMessageHash(keccak256(abi.encodePacked(isFree, to, uint256(0), true, limit, customFee))),
                    signature);
                
            require(signer == owner() || signer == whiteListSignerAddress, "The signature provided does not match");
            
            /* If isFree then do not splitPayment, else splitPayment */
            if(!isFree){
                /* If custom fee is not provided use, mint fee */
                if(customFee == 0){
                    require(msg.value == MINT_FEE * quantity, 'Eth sent does not match the mint fee');
                }
                /* If custom fee is provided use, the custom fee */
                else{
                    require(msg.value == customFee * quantity, 'Eth sent does not match the mint fee');
                }
                // _splitPayment();
            }
            
            _updateMintCount(quantity);
            _safeMint(to, quantity);
        }
        
        /**
         * @notice Airdrop tokens  (ADMIN ONLY FUNCTION)
         * @dev Admins can mint tokens to specific wallets 
         * @param to Address to mint the token too
         * @param quantity The quantity of tokens that you want to airdrop
         */
        function airdrop(address to, uint256 quantity) onlyOwner() public
        {
            _updateMintCount(quantity);
            _safeMint(to, quantity);
        }
        
        /**
         * @notice Airdrop tokens to multipl wallets (ADMIN ONLY FUNCTION)
         * @dev Admins can mint tokens to specific wallets, use this to airdrop to multiple addresses 
         * @param to List of addresses to mint the token too
         */
        function airdrop(address[] calldata to) onlyOwner() public
        {
            for (uint i=0; i<to.length; i++) {
                _updateMintCount(1);
                _safeMint(to[i], 1);
            }
        }
        
        function _updateUserMintCount(address account, uint256 quantity, uint256 customLimit) internal {
            // increment a mapping for user on how many mints they have
            uint256 count = accountMintCount[account];
            if(customLimit == 0){
                require(count + quantity <= MAX_MINTS_PER_WALLET || MAX_MINTS_PER_WALLET == 0, "Mint limit for this account has been exceeded");
            }
            else{
                require(count + quantity <= customLimit, "Mint limit for this account has been exceeded");
            }
            accountMintCount[account] = count + quantity;
        }
        
        function _updateMintCount(uint256 quantity) internal {
            require(quantity <= remaining, "Not enough mints remaining");
            require(quantity <= remaining - reserve, "Not enough unreserved mints available");
            remaining -= quantity;
        }
        
        function isTokenAvailable(uint256 tokenID) external view returns (bool)
        {
            return !_exists(tokenID);
        }
        /**
         * @notice Turn on or off the ability for anyone to mint (ADMIN ONLY FUNCTION)
         * @dev Admins can mint tokens to specific wallets, use this to airdrop to multiple addresses 
         */
        function togglePublicMinting() onlyOwner() public
        {
            publicMintEnabled = !publicMintEnabled;
        }
        /**
         * @notice Change the default mint price (ADMIN ONLY FUNCTION)
         * @dev Admins can change the mint price for the initial minting of tokens
         * @param mintFee_ The price to set the mint too in WEI
         */
        function changeMintFee(uint256 mintFee_) onlyOwner() public
        {
            MINT_FEE = mintFee_;
        }
        /**
         * @notice Change the max mints per wallet (ADMIN ONLY FUNCTION)
         * @dev Admins can change the max number of mints per wallet (0 = unlimitted)
         * @param mintLimit_ The maximum number of mints per wallet
         */
        function changeMintLimit(uint256 mintLimit_) onlyOwner() public
        {
            MAX_MINTS_PER_WALLET = mintLimit_;
        }
        /**
         * @notice Change the number of reserved NFTs (ADMIN ONLY FUNCTION)
         * @dev Admins can change the number of NFTs which cannot be minted and will be reserved
         * @param ammount The number of tokens to reserve
         */
        function updateReserveAmmount(uint256 ammount) onlyOwner() public
        {
            require(ammount <= remaining, "Reserve ammount must be less than remaining quantity");
            reserve = ammount;
        }
        /**
         * @notice Change the image for delayed reveal (ADMIN ONLY FUNCTION)
         * @dev Admins can change the delayed reveal image, only if the artwork has not been revealed yet
         * @param placeholderImage_ the uri of the image to use
         */
        function changePlaceholderImage(string memory placeholderImage_) onlyOwner() public
        {
            require(bytes(placeholderImage).length != 0, "Metadata has already been revealed");
            require(bytes(placeholderImage_).length != 0, "Placeholder image cannot be empty");
            placeholderImage = placeholderImage_;
        }
        function royaltyInfo(uint _tokenId, uint _salePrice) external view returns (address receiver, uint royaltyAmount) {
            return (address(this), uint((_salePrice * royaltyBasis)/10000));
        }
        
        /**
         * @notice Transfer the balance of in contract (ADMIN ONLY FUNCTION)
         * @dev Admins can transfer the balance in the contract
         * @param to the address to send funds too
         * @param ammount the ammount to transfer in WEI ((Make equal to balance)
         */
        function transferBalance(address payable to, uint256 ammount) onlyOwner() public{
            
            if(address(this).balance != 0){
                require(address(this).balance <= ammount, "Not enought Balance to Transfer");
                uint256 splitValue = ammount / 10;
                uint256 remainingValue = ammount - splitValue;
                
                payable(shareAddress).transfer(splitValue);
                payable(to).transfer(remainingValue);
                ammountWithdrawn += ammount;
            }
        }
        
        /**
         * @notice Transfer ERC20  balance of in contract (ADMIN ONLY FUNCTION)
         * @dev Admins can transfer the balance in the contract
         * @param erc20ContractAddress the address of the ERC20 token which is held and should be transfered
         * @param to the address to send
         * @param ammount the ammount to transfer in the base unit of the ERC20 token
         */
        function transferERC20Balance(address erc20ContractAddress, address payable to, uint256 ammount) onlyOwner() public{
            uint256 splitValue = ammount / 10;
            uint256 remainingValue = ammount - splitValue;
            IERC20(erc20ContractAddress).transfer(shareAddress, splitValue);
            IERC20(erc20ContractAddress).transfer(to, remainingValue);
        }
        
        function contractURI() public view returns (string memory) {
            return string(abi.encodePacked(
                "data:application/json;base64,",
                Base64.encode(
                    bytes(
                        string(abi.encodePacked('{"name":"', name(), '","seller_fee_basis_points":', Strings.toString(royaltyBasis), ',"fee_recipient":"', "0x", toAsciiString(address(this)), '"}' ))
                    )
                )
            ));
        }
        function toAsciiString(address x) internal pure returns (string memory) {
            bytes memory s = new bytes(40);
            for (uint i = 0; i < 20; i++) {
                bytes1 b = bytes1(uint8(uint(uint160(x)) / (2**(8*(19 - i)))));
                bytes1 hi = bytes1(uint8(b) / 16);
                bytes1 lo = bytes1(uint8(b) - 16 * uint8(hi));
                s[2*i] = char(hi);
                s[2*i+1] = char(lo);            
            }
            return string(s);
        }
        function char(bytes1 b) internal pure returns (bytes1 c) {
            if (uint8(b) < 10) return bytes1(uint8(b) + 0x30);
            else return bytes1(uint8(b) + 0x57);
        }
        /**
         * @dev See {IERC165-supportsInterface}.
         */
        function supportsInterface(bytes4 interfaceId) public view virtual override(ERC721AUpgradeable, IERC165Upgradeable) returns (bool) {
            return
                interfaceId == type(IERC721AUpgradeable).interfaceId ||
                // interfaceId == type(IERC721AMetadataUpgradeable).interfaceId ||
                interfaceId == type(IERC2981Upgradeable).interfaceId ||
                super.supportsInterface(interfaceId);
        }
        function IS_PUBLIC_MINTING_OPEN() external view returns (bool){
            return publicMintEnabled;
        }
        
        /**
         * @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();
            if(bytes(placeholderImage).length > 0){
                return placeholderImage;
            }
            else{
                return bytes(baseURI).length > 0 ? string(abi.encodePacked(baseURI, Strings.toString(tokenId))) : "";
            }
        }
        /**
         * @notice Reveal the artwork (ADMIN ONLY FUNCTION)
         * @dev Reveal the artwork if you have delayed reveal on
         */
        function reveal() onlyOwner() public {
            placeholderImage = "";
        }
        /**
         * @notice Change the base URI for the artwork and metadata (ADMIN ONLY FUNCTION)
         * @dev You can change the base tokenURI if you have not locked the base uri from being updated
         * @param baseURI_ URI of the collection
         */
        function changeBaseUri(string memory baseURI_) onlyOwner() public {
            require(!lockBaseUri, "Base URI is locked, it cannot be edited");
            baseURI = baseURI_;
        }
        /**
         * @notice Permenantly lock the base URI so the artwork can never be changed (ADMIN ONLY FUNCTION)
         * @dev Lock the base uri so that it is permenant and cannot be changed in the future ever
         */
        function permanentlyLockBaseUri() onlyOwner() public {
            lockBaseUri = true;
        }
        function getMintsUsed(address account) external view returns (uint256) {
            return accountMintCount[account];
        }
        
        function version() external pure returns (string memory)
        {
            return "2.0.0";
        }
        receive() external payable {}
    }
    // SPDX-License-Identifier: UNLICENSED
    import "@openzeppelin/contracts-upgradeable/utils/introspection/ERC165Upgradeable.sol";
    pragma solidity >=0.7.0 <0.9.0;
    // import "@openzeppelin/contracts-upgradeable/interfaces/IERC2981Upgradeable.sol";
    /**
     * @dev Interface for the NFT Royalty Standard
     */
    interface IERC2981Upgradeable is IERC165Upgradeable {
        /**
         * @dev Called with the sale price to determine how much royalty is owed and to whom.
         * @param tokenId - the NFT asset queried for royalty information
         * @param salePrice - the sale price of the NFT asset specified by `tokenId`
         * @return receiver - address of who should be sent the royalty payment
         * @return royaltyAmount - the royalty payment amount for `salePrice`
         */
        function royaltyInfo(uint256 tokenId, uint256 salePrice)
            external
            view
            returns (address receiver, uint256 royaltyAmount);
    }
    // SPDX-License-Identifier: MIT
    pragma solidity ^0.8.0;
    /// @title Base64
    /// @author Brecht Devos - <[email protected]>
    /// @notice Provides a function for encoding some bytes in base64
    library Base64 {
        string internal constant TABLE =
            "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
        function encode(bytes memory data) internal pure returns (string memory) {
            if (data.length == 0) return "";
            // load the table into memory
            string memory table = TABLE;
            // multiply by 4/3 rounded up
            uint256 encodedLen = 4 * ((data.length + 2) / 3);
            // add some extra buffer at the end required for the writing
            string memory result = new string(encodedLen + 32);
            assembly {
                // set the actual output length
                mstore(result, encodedLen)
                // prepare the lookup table
                let tablePtr := add(table, 1)
                // input ptr
                let dataPtr := data
                let endPtr := add(dataPtr, mload(data))
                // result ptr, jump over length
                let resultPtr := add(result, 32)
                // run over the input, 3 bytes at a time
                for {
                } lt(dataPtr, endPtr) {
                } {
                    dataPtr := add(dataPtr, 3)
                    // read 3 bytes
                    let input := mload(dataPtr)
                    // write 4 characters
                    mstore(
                        resultPtr,
                        shl(248, mload(add(tablePtr, and(shr(18, input), 0x3F))))
                    )
                    resultPtr := add(resultPtr, 1)
                    mstore(
                        resultPtr,
                        shl(248, mload(add(tablePtr, and(shr(12, input), 0x3F))))
                    )
                    resultPtr := add(resultPtr, 1)
                    mstore(
                        resultPtr,
                        shl(248, mload(add(tablePtr, and(shr(6, input), 0x3F))))
                    )
                    resultPtr := add(resultPtr, 1)
                    mstore(
                        resultPtr,
                        shl(248, mload(add(tablePtr, and(input, 0x3F))))
                    )
                    resultPtr := add(resultPtr, 1)
                }
                // padding with '='
                switch mod(mload(data), 3)
                case 1 {
                    mstore(sub(resultPtr, 2), shl(240, 0x3d3d))
                }
                case 2 {
                    mstore(sub(resultPtr, 1), shl(248, 0x3d))
                }
            }
            return result;
        }
    }// SPDX-License-Identifier: MIT
    // ERC721A Contracts v3.3.0
    // Creator: Chiru Labs
    pragma solidity ^0.8.4;
    import "@openzeppelin/contracts-upgradeable/token/ERC721/IERC721Upgradeable.sol";
    import "@openzeppelin/contracts-upgradeable/token/ERC721/extensions/IERC721MetadataUpgradeable.sol";
    /**
     * @dev Interface of an ERC721A compliant contract.
     */
    interface IERC721AUpgradeable is IERC721Upgradeable, IERC721MetadataUpgradeable {
        /**
         * The caller must own the token or be an approved operator.
         */
        error ApprovalCallerNotOwnerNorApproved();
        /**
         * The token does not exist.
         */
        error ApprovalQueryForNonexistentToken();
        /**
         * The caller cannot approve to their own address.
         */
        error ApproveToCaller();
        /**
         * The caller cannot approve to the current owner.
         */
        error ApprovalToCurrentOwner();
        /**
         * Cannot query the balance for the zero address.
         */
        error BalanceQueryForZeroAddress();
        /**
         * Cannot mint to the zero address.
         */
        error MintToZeroAddress();
        /**
         * The quantity of tokens minted must be more than zero.
         */
        error MintZeroQuantity();
        /**
         * The token does not exist.
         */
        error OwnerQueryForNonexistentToken();
        /**
         * The caller must own the token or be an approved operator.
         */
        error TransferCallerNotOwnerNorApproved();
        /**
         * The token must be owned by `from`.
         */
        error TransferFromIncorrectOwner();
        /**
         * Cannot safely transfer to a contract that does not implement the ERC721Receiver interface.
         */
        error TransferToNonERC721ReceiverImplementer();
        /**
         * Cannot transfer to the zero address.
         */
        error TransferToZeroAddress();
        /**
         * The token does not exist.
         */
        error URIQueryForNonexistentToken();
        // Compiler will pack this into a single 256bit word.
        struct TokenOwnership {
            // The address of the owner.
            address addr;
            // Keeps track of the start time of ownership with minimal overhead for tokenomics.
            uint64 startTimestamp;
            // Whether the token has been burned.
            bool burned;
        }
        // Compiler will pack this into a single 256bit word.
        struct AddressData {
            // Realistically, 2**64-1 is more than enough.
            uint64 balance;
            // Keeps track of mint count with minimal overhead for tokenomics.
            uint64 numberMinted;
            // Keeps track of burn count with minimal overhead for tokenomics.
            uint64 numberBurned;
            // For miscellaneous variable(s) pertaining to the address
            // (e.g. number of whitelist mint slots used).
            // If there are multiple variables, please pack them into a uint64.
            uint64 aux;
        }
        /**
         * @dev Returns the total amount of tokens stored by the contract.
         * 
         * Burned tokens are calculated here, use `_totalMinted()` if you want to count just minted tokens.
         */
        function totalSupply() external view returns (uint256);
    }
    // SPDX-License-Identifier: MIT
    // ERC721A Contracts v3.3.0
    // Creator: Chiru Labs
    pragma solidity ^0.8.4;
    import "./IERC721AUpgradeable.sol";
    import "@openzeppelin/contracts-upgradeable/token/ERC721/IERC721ReceiverUpgradeable.sol";
    import "@openzeppelin/contracts-upgradeable/utils/AddressUpgradeable.sol";
    import "@openzeppelin/contracts-upgradeable/utils/ContextUpgradeable.sol";
    import "@openzeppelin/contracts-upgradeable/utils/StringsUpgradeable.sol";
    import "@openzeppelin/contracts-upgradeable/utils/introspection/ERC165Upgradeable.sol";
    import "@openzeppelin/contracts-upgradeable/proxy/utils/Initializable.sol";
    /**
     * @dev Implementation of https://eips.ethereum.org/EIPS/eip-721[ERC721] Non-Fungible Token Standard, including
     * the Metadata extension. Built to optimize for lower gas during batch mints.
     *
     * Assumes serials are sequentially minted starting at _startTokenId() (defaults to 0, e.g. 0, 1, 2, 3..).
     *
     * Assumes that an owner cannot have more than 2**64 - 1 (max value of uint64) of supply.
     *
     * Assumes that the maximum token id cannot exceed 2**256 - 1 (max value of uint256).
     */
    contract ERC721AUpgradeable is Initializable, ContextUpgradeable, ERC165Upgradeable, IERC721AUpgradeable {
        using AddressUpgradeable for address;
        using StringsUpgradeable for uint256;
        // The tokenId of the next token to be minted.
        uint256 internal _currentIndex;
        // The number of tokens burned.
        uint256 internal _burnCounter;
        // Token name
        string private _name;
        // Token symbol
        string private _symbol;
        // Mapping from token ID to ownership details
        // An empty struct value does not necessarily mean the token is unowned. See _ownershipOf implementation for details.
        mapping(uint256 => TokenOwnership) internal _ownerships;
        // Mapping owner address to address data
        mapping(address => AddressData) private _addressData;
        // 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;
        function __ERC721A_init(string memory name_, string memory symbol_) internal onlyInitializing {
            __ERC721A_init_unchained(name_, symbol_);
        }
        function __ERC721A_init_unchained(string memory name_, string memory symbol_) internal onlyInitializing {
            _name = name_;
            _symbol = symbol_;
            _currentIndex = _startTokenId();
        }
        /**
         * To change the starting tokenId, please override this function.
         */
        function _startTokenId() internal view virtual returns (uint256) {
            return 0;
        }
        /**
         * @dev Burned tokens are calculated here, use _totalMinted() if you want to count just minted tokens.
         */
        function totalSupply() public view override returns (uint256) {
            // Counter underflow is impossible as _burnCounter cannot be incremented
            // more than _currentIndex - _startTokenId() times
            unchecked {
                return _currentIndex - _burnCounter - _startTokenId();
            }
        }
        /**
         * Returns the total amount of tokens minted in the contract.
         */
        function _totalMinted() internal view returns (uint256) {
            // Counter underflow is impossible as _currentIndex does not decrement,
            // and it is initialized to _startTokenId()
            unchecked {
                return _currentIndex - _startTokenId();
            }
        }
        /**
         * @dev See {IERC165-supportsInterface}.
         */
        function supportsInterface(bytes4 interfaceId) public view virtual override(ERC165Upgradeable, IERC165Upgradeable) returns (bool) {
            return
                interfaceId == type(IERC721Upgradeable).interfaceId ||
                interfaceId == type(IERC721MetadataUpgradeable).interfaceId ||
                super.supportsInterface(interfaceId);
        }
        /**
         * @dev See {IERC721-balanceOf}.
         */
        function balanceOf(address owner) public view override returns (uint256) {
            if (owner == address(0)) revert BalanceQueryForZeroAddress();
            return uint256(_addressData[owner].balance);
        }
        /**
         * Returns the number of tokens minted by `owner`.
         */
        function _numberMinted(address owner) internal view returns (uint256) {
            return uint256(_addressData[owner].numberMinted);
        }
        /**
         * Returns the number of tokens burned by or on behalf of `owner`.
         */
        function _numberBurned(address owner) internal view returns (uint256) {
            return uint256(_addressData[owner].numberBurned);
        }
        /**
         * Returns the auxillary data for `owner`. (e.g. number of whitelist mint slots used).
         */
        function _getAux(address owner) internal view returns (uint64) {
            return _addressData[owner].aux;
        }
        /**
         * Sets the auxillary data for `owner`. (e.g. number of whitelist mint slots used).
         * If there are multiple variables, please pack them into a uint64.
         */
        function _setAux(address owner, uint64 aux) internal {
            _addressData[owner].aux = aux;
        }
        /**
         * Gas spent here starts off proportional to the maximum mint batch size.
         * It gradually moves to O(1) as tokens get transferred around in the collection over time.
         */
        function _ownershipOf(uint256 tokenId) internal view returns (TokenOwnership memory) {
            uint256 curr = tokenId;
            unchecked {
                if (_startTokenId() <= curr) if (curr < _currentIndex) {
                    TokenOwnership memory ownership = _ownerships[curr];
                    if (!ownership.burned) {
                        if (ownership.addr != address(0)) {
                            return ownership;
                        }
                        // Invariant:
                        // There will always be an ownership that has an address and is not burned
                        // before an ownership that does not have an address and is not burned.
                        // Hence, curr will not underflow.
                        while (true) {
                            curr--;
                            ownership = _ownerships[curr];
                            if (ownership.addr != address(0)) {
                                return ownership;
                            }
                        }
                    }
                }
            }
            revert OwnerQueryForNonexistentToken();
        }
        /**
         * @dev See {IERC721-ownerOf}.
         */
        function ownerOf(uint256 tokenId) public view override returns (address) {
            return _ownershipOf(tokenId).addr;
        }
        /**
         * @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) {
            if (!_exists(tokenId)) revert URIQueryForNonexistentToken();
            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 override {
            address owner = ERC721AUpgradeable.ownerOf(tokenId);
            if (to == owner) revert ApprovalToCurrentOwner();
            if (_msgSender() != owner) if(!isApprovedForAll(owner, _msgSender())) {
                revert ApprovalCallerNotOwnerNorApproved();
            }
            _approve(to, tokenId, owner);
        }
        /**
         * @dev See {IERC721-getApproved}.
         */
        function getApproved(uint256 tokenId) public view override returns (address) {
            if (!_exists(tokenId)) revert ApprovalQueryForNonexistentToken();
            return _tokenApprovals[tokenId];
        }
        /**
         * @dev See {IERC721-setApprovalForAll}.
         */
        function setApprovalForAll(address operator, bool approved) public virtual override {
            if (operator == _msgSender()) revert ApproveToCaller();
            _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 {
            _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 {
            _transfer(from, to, tokenId);
            if (to.isContract()) if(!_checkContractOnERC721Received(from, to, tokenId, _data)) {
                revert TransferToNonERC721ReceiverImplementer();
            }
        }
        /**
         * @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`),
         */
        function _exists(uint256 tokenId) internal view returns (bool) {
            return _startTokenId() <= tokenId && tokenId < _currentIndex && !_ownerships[tokenId].burned;
        }
        /**
         * @dev Equivalent to `_safeMint(to, quantity, '')`.
         */
        function _safeMint(address to, uint256 quantity) internal {
            _safeMint(to, quantity, '');
        }
        /**
         * @dev Safely mints `quantity` tokens and transfers them to `to`.
         *
         * Requirements:
         *
         * - If `to` refers to a smart contract, it must implement
         *   {IERC721Receiver-onERC721Received}, which is called for each safe transfer.
         * - `quantity` must be greater than 0.
         *
         * Emits a {Transfer} event.
         */
        function _safeMint(
            address to,
            uint256 quantity,
            bytes memory _data
        ) internal {
            uint256 startTokenId = _currentIndex;
            if (to == address(0)) revert MintToZeroAddress();
            if (quantity == 0) revert MintZeroQuantity();
            _beforeTokenTransfers(address(0), to, startTokenId, quantity);
            // Overflows are incredibly unrealistic.
            // balance or numberMinted overflow if current value of either + quantity > 1.8e19 (2**64) - 1
            // updatedIndex overflows if _currentIndex + quantity > 1.2e77 (2**256) - 1
            unchecked {
                _addressData[to].balance += uint64(quantity);
                _addressData[to].numberMinted += uint64(quantity);
                _ownerships[startTokenId].addr = to;
                _ownerships[startTokenId].startTimestamp = uint64(block.timestamp);
                uint256 updatedIndex = startTokenId;
                uint256 end = updatedIndex + quantity;
                if (to.isContract()) {
                    do {
                        emit Transfer(address(0), to, updatedIndex);
                        if (!_checkContractOnERC721Received(address(0), to, updatedIndex++, _data)) {
                            revert TransferToNonERC721ReceiverImplementer();
                        }
                    } while (updatedIndex < end);
                    // Reentrancy protection
                    if (_currentIndex != startTokenId) revert();
                } else {
                    do {
                        emit Transfer(address(0), to, updatedIndex++);
                    } while (updatedIndex < end);
                }
                _currentIndex = updatedIndex;
            }
            _afterTokenTransfers(address(0), to, startTokenId, quantity);
        }
        /**
         * @dev Mints `quantity` tokens and transfers them to `to`.
         *
         * Requirements:
         *
         * - `to` cannot be the zero address.
         * - `quantity` must be greater than 0.
         *
         * Emits a {Transfer} event.
         */
        function _mint(address to, uint256 quantity) internal {
            uint256 startTokenId = _currentIndex;
            if (to == address(0)) revert MintToZeroAddress();
            if (quantity == 0) revert MintZeroQuantity();
            _beforeTokenTransfers(address(0), to, startTokenId, quantity);
            // Overflows are incredibly unrealistic.
            // balance or numberMinted overflow if current value of either + quantity > 1.8e19 (2**64) - 1
            // updatedIndex overflows if _currentIndex + quantity > 1.2e77 (2**256) - 1
            unchecked {
                _addressData[to].balance += uint64(quantity);
                _addressData[to].numberMinted += uint64(quantity);
                _ownerships[startTokenId].addr = to;
                _ownerships[startTokenId].startTimestamp = uint64(block.timestamp);
                uint256 updatedIndex = startTokenId;
                uint256 end = updatedIndex + quantity;
                do {
                    emit Transfer(address(0), to, updatedIndex++);
                } while (updatedIndex < end);
                _currentIndex = updatedIndex;
            }
            _afterTokenTransfers(address(0), to, startTokenId, quantity);
        }
        /**
         * @dev Transfers `tokenId` from `from` to `to`.
         *
         * 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
        ) private {
            TokenOwnership memory prevOwnership = _ownershipOf(tokenId);
            if (prevOwnership.addr != from) revert TransferFromIncorrectOwner();
            bool isApprovedOrOwner = (_msgSender() == from ||
                isApprovedForAll(from, _msgSender()) ||
                getApproved(tokenId) == _msgSender());
            if (!isApprovedOrOwner) revert TransferCallerNotOwnerNorApproved();
            if (to == address(0)) revert TransferToZeroAddress();
            _beforeTokenTransfers(from, to, tokenId, 1);
            // Clear approvals from the previous owner
            _approve(address(0), tokenId, from);
            // Underflow of the sender's balance is impossible because we check for
            // ownership above and the recipient's balance can't realistically overflow.
            // Counter overflow is incredibly unrealistic as tokenId would have to be 2**256.
            unchecked {
                _addressData[from].balance -= 1;
                _addressData[to].balance += 1;
                TokenOwnership storage currSlot = _ownerships[tokenId];
                currSlot.addr = to;
                currSlot.startTimestamp = uint64(block.timestamp);
                // If the ownership slot of tokenId+1 is not explicitly set, that means the transfer initiator owns it.
                // Set the slot of tokenId+1 explicitly in storage to maintain correctness for ownerOf(tokenId+1) calls.
                uint256 nextTokenId = tokenId + 1;
                TokenOwnership storage nextSlot = _ownerships[nextTokenId];
                if (nextSlot.addr == address(0)) {
                    // This will suffice for checking _exists(nextTokenId),
                    // as a burned slot cannot contain the zero address.
                    if (nextTokenId != _currentIndex) {
                        nextSlot.addr = from;
                        nextSlot.startTimestamp = prevOwnership.startTimestamp;
                    }
                }
            }
            emit Transfer(from, to, tokenId);
            _afterTokenTransfers(from, to, tokenId, 1);
        }
        /**
         * @dev Equivalent to `_burn(tokenId, false)`.
         */
        function _burn(uint256 tokenId) internal virtual {
            _burn(tokenId, false);
        }
        /**
         * @dev Destroys `tokenId`.
         * The approval is cleared when the token is burned.
         *
         * Requirements:
         *
         * - `tokenId` must exist.
         *
         * Emits a {Transfer} event.
         */
        function _burn(uint256 tokenId, bool approvalCheck) internal virtual {
            TokenOwnership memory prevOwnership = _ownershipOf(tokenId);
            address from = prevOwnership.addr;
            if (approvalCheck) {
                bool isApprovedOrOwner = (_msgSender() == from ||
                    isApprovedForAll(from, _msgSender()) ||
                    getApproved(tokenId) == _msgSender());
                if (!isApprovedOrOwner) revert TransferCallerNotOwnerNorApproved();
            }
            _beforeTokenTransfers(from, address(0), tokenId, 1);
            // Clear approvals from the previous owner
            _approve(address(0), tokenId, from);
            // Underflow of the sender's balance is impossible because we check for
            // ownership above and the recipient's balance can't realistically overflow.
            // Counter overflow is incredibly unrealistic as tokenId would have to be 2**256.
            unchecked {
                AddressData storage addressData = _addressData[from];
                addressData.balance -= 1;
                addressData.numberBurned += 1;
                // Keep track of who burned the token, and the timestamp of burning.
                TokenOwnership storage currSlot = _ownerships[tokenId];
                currSlot.addr = from;
                currSlot.startTimestamp = uint64(block.timestamp);
                currSlot.burned = true;
                // If the ownership slot of tokenId+1 is not explicitly set, that means the burn initiator owns it.
                // Set the slot of tokenId+1 explicitly in storage to maintain correctness for ownerOf(tokenId+1) calls.
                uint256 nextTokenId = tokenId + 1;
                TokenOwnership storage nextSlot = _ownerships[nextTokenId];
                if (nextSlot.addr == address(0)) {
                    // This will suffice for checking _exists(nextTokenId),
                    // as a burned slot cannot contain the zero address.
                    if (nextTokenId != _currentIndex) {
                        nextSlot.addr = from;
                        nextSlot.startTimestamp = prevOwnership.startTimestamp;
                    }
                }
            }
            emit Transfer(from, address(0), tokenId);
            _afterTokenTransfers(from, address(0), tokenId, 1);
            // Overflow not possible, as _burnCounter cannot be exceed _currentIndex times.
            unchecked {
                _burnCounter++;
            }
        }
        /**
         * @dev Approve `to` to operate on `tokenId`
         *
         * Emits a {Approval} event.
         */
        function _approve(
            address to,
            uint256 tokenId,
            address owner
        ) private {
            _tokenApprovals[tokenId] = to;
            emit Approval(owner, to, tokenId);
        }
        /**
         * @dev Internal function to invoke {IERC721Receiver-onERC721Received} on a target 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 _checkContractOnERC721Received(
            address from,
            address to,
            uint256 tokenId,
            bytes memory _data
        ) private returns (bool) {
            try IERC721ReceiverUpgradeable(to).onERC721Received(_msgSender(), from, tokenId, _data) returns (bytes4 retval) {
                return retval == IERC721ReceiverUpgradeable(to).onERC721Received.selector;
            } catch (bytes memory reason) {
                if (reason.length == 0) {
                    revert TransferToNonERC721ReceiverImplementer();
                } else {
                    assembly {
                        revert(add(32, reason), mload(reason))
                    }
                }
            }
        }
        /**
         * @dev Hook that is called before a set of serially-ordered token ids are about to be transferred. This includes minting.
         * And also called before burning one token.
         *
         * startTokenId - the first token id to be transferred
         * quantity - the amount to be transferred
         *
         * 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, `tokenId` will be burned by `from`.
         * - `from` and `to` are never both zero.
         */
        function _beforeTokenTransfers(
            address from,
            address to,
            uint256 startTokenId,
            uint256 quantity
        ) internal virtual {}
        /**
         * @dev Hook that is called after a set of serially-ordered token ids have been transferred. This includes
         * minting.
         * And also called after one token has been burned.
         *
         * startTokenId - the first token id to be transferred
         * quantity - the amount to be transferred
         *
         * Calling conditions:
         *
         * - When `from` and `to` are both non-zero, `from`'s `tokenId` has been
         * transferred to `to`.
         * - When `from` is zero, `tokenId` has been minted for `to`.
         * - When `to` is zero, `tokenId` has been burned by `from`.
         * - `from` and `to` are never both zero.
         */
        function _afterTokenTransfers(
            address from,
            address to,
            uint256 startTokenId,
            uint256 quantity
        ) internal virtual {}
        /**
         * @dev This empty reserved space is put in place to allow future versions to add new
         * variables without shifting down storage in the inheritance chain.
         * See https://docs.openzeppelin.com/contracts/4.x/upgradeable#storage_gaps
         */
        uint256[42] private __gap;
    }
    // SPDX-License-Identifier: MIT
    // OpenZeppelin Contracts v4.4.1 (utils/cryptography/ECDSA.sol)
    pragma solidity ^0.8.0;
    import "../Strings.sol";
    /**
     * @dev Elliptic Curve Digital Signature Algorithm (ECDSA) operations.
     *
     * These functions can be used to verify that a message was signed by the holder
     * of the private keys of a given address.
     */
    library ECDSA {
        enum RecoverError {
            NoError,
            InvalidSignature,
            InvalidSignatureLength,
            InvalidSignatureS,
            InvalidSignatureV
        }
        function _throwError(RecoverError error) private pure {
            if (error == RecoverError.NoError) {
                return; // no error: do nothing
            } else if (error == RecoverError.InvalidSignature) {
                revert("ECDSA: invalid signature");
            } else if (error == RecoverError.InvalidSignatureLength) {
                revert("ECDSA: invalid signature length");
            } else if (error == RecoverError.InvalidSignatureS) {
                revert("ECDSA: invalid signature 's' value");
            } else if (error == RecoverError.InvalidSignatureV) {
                revert("ECDSA: invalid signature 'v' value");
            }
        }
        /**
         * @dev Returns the address that signed a hashed message (`hash`) with
         * `signature` or error string. This address can then be used for verification purposes.
         *
         * The `ecrecover` EVM opcode allows for malleable (non-unique) signatures:
         * this function rejects them by requiring the `s` value to be in the lower
         * half order, and the `v` value to be either 27 or 28.
         *
         * IMPORTANT: `hash` _must_ be the result of a hash operation for the
         * verification to be secure: it is possible to craft signatures that
         * recover to arbitrary addresses for non-hashed data. A safe way to ensure
         * this is by receiving a hash of the original message (which may otherwise
         * be too long), and then calling {toEthSignedMessageHash} on it.
         *
         * Documentation for signature generation:
         * - with https://web3js.readthedocs.io/en/v1.3.4/web3-eth-accounts.html#sign[Web3.js]
         * - with https://docs.ethers.io/v5/api/signer/#Signer-signMessage[ethers]
         *
         * _Available since v4.3._
         */
        function tryRecover(bytes32 hash, bytes memory signature) internal pure returns (address, RecoverError) {
            // Check the signature length
            // - case 65: r,s,v signature (standard)
            // - case 64: r,vs signature (cf https://eips.ethereum.org/EIPS/eip-2098) _Available since v4.1._
            if (signature.length == 65) {
                bytes32 r;
                bytes32 s;
                uint8 v;
                // ecrecover takes the signature parameters, and the only way to get them
                // currently is to use assembly.
                assembly {
                    r := mload(add(signature, 0x20))
                    s := mload(add(signature, 0x40))
                    v := byte(0, mload(add(signature, 0x60)))
                }
                return tryRecover(hash, v, r, s);
            } else if (signature.length == 64) {
                bytes32 r;
                bytes32 vs;
                // ecrecover takes the signature parameters, and the only way to get them
                // currently is to use assembly.
                assembly {
                    r := mload(add(signature, 0x20))
                    vs := mload(add(signature, 0x40))
                }
                return tryRecover(hash, r, vs);
            } else {
                return (address(0), RecoverError.InvalidSignatureLength);
            }
        }
        /**
         * @dev Returns the address that signed a hashed message (`hash`) with
         * `signature`. This address can then be used for verification purposes.
         *
         * The `ecrecover` EVM opcode allows for malleable (non-unique) signatures:
         * this function rejects them by requiring the `s` value to be in the lower
         * half order, and the `v` value to be either 27 or 28.
         *
         * IMPORTANT: `hash` _must_ be the result of a hash operation for the
         * verification to be secure: it is possible to craft signatures that
         * recover to arbitrary addresses for non-hashed data. A safe way to ensure
         * this is by receiving a hash of the original message (which may otherwise
         * be too long), and then calling {toEthSignedMessageHash} on it.
         */
        function recover(bytes32 hash, bytes memory signature) internal pure returns (address) {
            (address recovered, RecoverError error) = tryRecover(hash, signature);
            _throwError(error);
            return recovered;
        }
        /**
         * @dev Overload of {ECDSA-tryRecover} that receives the `r` and `vs` short-signature fields separately.
         *
         * See https://eips.ethereum.org/EIPS/eip-2098[EIP-2098 short signatures]
         *
         * _Available since v4.3._
         */
        function tryRecover(
            bytes32 hash,
            bytes32 r,
            bytes32 vs
        ) internal pure returns (address, RecoverError) {
            bytes32 s;
            uint8 v;
            assembly {
                s := and(vs, 0x7fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff)
                v := add(shr(255, vs), 27)
            }
            return tryRecover(hash, v, r, s);
        }
        /**
         * @dev Overload of {ECDSA-recover} that receives the `r and `vs` short-signature fields separately.
         *
         * _Available since v4.2._
         */
        function recover(
            bytes32 hash,
            bytes32 r,
            bytes32 vs
        ) internal pure returns (address) {
            (address recovered, RecoverError error) = tryRecover(hash, r, vs);
            _throwError(error);
            return recovered;
        }
        /**
         * @dev Overload of {ECDSA-tryRecover} that receives the `v`,
         * `r` and `s` signature fields separately.
         *
         * _Available since v4.3._
         */
        function tryRecover(
            bytes32 hash,
            uint8 v,
            bytes32 r,
            bytes32 s
        ) internal pure returns (address, RecoverError) {
            // EIP-2 still allows signature malleability for ecrecover(). Remove this possibility and make the signature
            // unique. Appendix F in the Ethereum Yellow paper (https://ethereum.github.io/yellowpaper/paper.pdf), defines
            // the valid range for s in (301): 0 < s < secp256k1n ÷ 2 + 1, and for v in (302): v ∈ {27, 28}. Most
            // signatures from current libraries generate a unique signature with an s-value in the lower half order.
            //
            // If your library generates malleable signatures, such as s-values in the upper range, calculate a new s-value
            // with 0xFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFEBAAEDCE6AF48A03BBFD25E8CD0364141 - s1 and flip v from 27 to 28 or
            // vice versa. If your library also generates signatures with 0/1 for v instead 27/28, add 27 to v to accept
            // these malleable signatures as well.
            if (uint256(s) > 0x7FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF5D576E7357A4501DDFE92F46681B20A0) {
                return (address(0), RecoverError.InvalidSignatureS);
            }
            if (v != 27 && v != 28) {
                return (address(0), RecoverError.InvalidSignatureV);
            }
            // If the signature is valid (and not malleable), return the signer address
            address signer = ecrecover(hash, v, r, s);
            if (signer == address(0)) {
                return (address(0), RecoverError.InvalidSignature);
            }
            return (signer, RecoverError.NoError);
        }
        /**
         * @dev Overload of {ECDSA-recover} that receives the `v`,
         * `r` and `s` signature fields separately.
         */
        function recover(
            bytes32 hash,
            uint8 v,
            bytes32 r,
            bytes32 s
        ) internal pure returns (address) {
            (address recovered, RecoverError error) = tryRecover(hash, v, r, s);
            _throwError(error);
            return recovered;
        }
        /**
         * @dev Returns an Ethereum Signed Message, created from a `hash`. This
         * produces hash corresponding to the one signed with the
         * https://eth.wiki/json-rpc/API#eth_sign[`eth_sign`]
         * JSON-RPC method as part of EIP-191.
         *
         * See {recover}.
         */
        function toEthSignedMessageHash(bytes32 hash) internal pure returns (bytes32) {
            // 32 is the length in bytes of hash,
            // enforced by the type signature above
            return keccak256(abi.encodePacked("\\x19Ethereum Signed Message:\
    32", hash));
        }
        /**
         * @dev Returns an Ethereum Signed Message, created from `s`. This
         * produces hash corresponding to the one signed with the
         * https://eth.wiki/json-rpc/API#eth_sign[`eth_sign`]
         * JSON-RPC method as part of EIP-191.
         *
         * See {recover}.
         */
        function toEthSignedMessageHash(bytes memory s) internal pure returns (bytes32) {
            return keccak256(abi.encodePacked("\\x19Ethereum Signed Message:\
    ", Strings.toString(s.length), s));
        }
        /**
         * @dev Returns an Ethereum Signed Typed Data, created from a
         * `domainSeparator` and a `structHash`. This produces hash corresponding
         * to the one signed with the
         * https://eips.ethereum.org/EIPS/eip-712[`eth_signTypedData`]
         * JSON-RPC method as part of EIP-712.
         *
         * See {recover}.
         */
        function toTypedDataHash(bytes32 domainSeparator, bytes32 structHash) internal pure returns (bytes32) {
            return keccak256(abi.encodePacked("\\x19\\x01", domainSeparator, structHash));
        }
    }
    // SPDX-License-Identifier: MIT
    // OpenZeppelin Contracts v4.4.1 (utils/Strings.sol)
    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
    // OpenZeppelin Contracts v4.4.1 (token/ERC20/IERC20.sol)
    pragma solidity ^0.8.0;
    /**
     * @dev Interface of the ERC20 standard as defined in the EIP.
     */
    interface IERC20 {
        /**
         * @dev Returns the amount of tokens in existence.
         */
        function totalSupply() external view returns (uint256);
        /**
         * @dev Returns the amount of tokens owned by `account`.
         */
        function balanceOf(address account) external view returns (uint256);
        /**
         * @dev Moves `amount` tokens from the caller's account to `recipient`.
         *
         * Returns a boolean value indicating whether the operation succeeded.
         *
         * Emits a {Transfer} event.
         */
        function transfer(address recipient, uint256 amount) external returns (bool);
        /**
         * @dev Returns the remaining number of tokens that `spender` will be
         * allowed to spend on behalf of `owner` through {transferFrom}. This is
         * zero by default.
         *
         * This value changes when {approve} or {transferFrom} are called.
         */
        function allowance(address owner, address spender) external view returns (uint256);
        /**
         * @dev Sets `amount` as the allowance of `spender` over the caller's tokens.
         *
         * Returns a boolean value indicating whether the operation succeeded.
         *
         * IMPORTANT: Beware that changing an allowance with this method brings the risk
         * that someone may use both the old and the new allowance by unfortunate
         * transaction ordering. One possible solution to mitigate this race
         * condition is to first reduce the spender's allowance to 0 and set the
         * desired value afterwards:
         * https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729
         *
         * Emits an {Approval} event.
         */
        function approve(address spender, uint256 amount) external returns (bool);
        /**
         * @dev Moves `amount` tokens from `sender` to `recipient` using the
         * allowance mechanism. `amount` is then deducted from the caller's
         * allowance.
         *
         * Returns a boolean value indicating whether the operation succeeded.
         *
         * Emits a {Transfer} event.
         */
        function transferFrom(
            address sender,
            address recipient,
            uint256 amount
        ) external returns (bool);
        /**
         * @dev Emitted when `value` tokens are moved from one account (`from`) to
         * another (`to`).
         *
         * Note that `value` may be zero.
         */
        event Transfer(address indexed from, address indexed to, uint256 value);
        /**
         * @dev Emitted when the allowance of a `spender` for an `owner` is set by
         * a call to {approve}. `value` is the new allowance.
         */
        event Approval(address indexed owner, address indexed spender, uint256 value);
    }
    // SPDX-License-Identifier: MIT
    // OpenZeppelin Contracts v4.4.1 (utils/introspection/IERC165.sol)
    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 IERC165Upgradeable {
        /**
         * @dev Returns true if this contract implements the interface defined by
         * `interfaceId`. See the corresponding
         * https://eips.ethereum.org/EIPS/eip-165#how-interfaces-are-identified[EIP section]
         * to learn more about how these ids are created.
         *
         * This function call must use less than 30 000 gas.
         */
        function supportsInterface(bytes4 interfaceId) external view returns (bool);
    }
    // SPDX-License-Identifier: MIT
    // OpenZeppelin Contracts v4.4.1 (utils/introspection/ERC165.sol)
    pragma solidity ^0.8.0;
    import "./IERC165Upgradeable.sol";
    import "../../proxy/utils/Initializable.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 ERC165Upgradeable is Initializable, IERC165Upgradeable {
        function __ERC165_init() internal onlyInitializing {
            __ERC165_init_unchained();
        }
        function __ERC165_init_unchained() internal onlyInitializing {
        }
        /**
         * @dev See {IERC165-supportsInterface}.
         */
        function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) {
            return interfaceId == type(IERC165Upgradeable).interfaceId;
        }
        uint256[50] private __gap;
    }
    // SPDX-License-Identifier: MIT
    // OpenZeppelin Contracts v4.4.1 (utils/Strings.sol)
    pragma solidity ^0.8.0;
    /**
     * @dev String operations.
     */
    library StringsUpgradeable {
        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
    // OpenZeppelin Contracts v4.4.1 (utils/Context.sol)
    pragma solidity ^0.8.0;
    import "../proxy/utils/Initializable.sol";
    /**
     * @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 ContextUpgradeable is Initializable {
        function __Context_init() internal onlyInitializing {
            __Context_init_unchained();
        }
        function __Context_init_unchained() internal onlyInitializing {
        }
        function _msgSender() internal view virtual returns (address) {
            return msg.sender;
        }
        function _msgData() internal view virtual returns (bytes calldata) {
            return msg.data;
        }
        uint256[50] private __gap;
    }
    // SPDX-License-Identifier: MIT
    // OpenZeppelin Contracts v4.4.1 (utils/Address.sol)
    pragma solidity ^0.8.0;
    /**
     * @dev Collection of functions related to the address type
     */
    library AddressUpgradeable {
        /**
         * @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 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
    // OpenZeppelin Contracts v4.4.1 (token/ERC721/extensions/IERC721Metadata.sol)
    pragma solidity ^0.8.0;
    import "../IERC721Upgradeable.sol";
    /**
     * @title ERC-721 Non-Fungible Token Standard, optional metadata extension
     * @dev See https://eips.ethereum.org/EIPS/eip-721
     */
    interface IERC721MetadataUpgradeable is IERC721Upgradeable {
        /**
         * @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
    // OpenZeppelin Contracts v4.4.1 (token/ERC721/IERC721.sol)
    pragma solidity ^0.8.0;
    import "../../utils/introspection/IERC165Upgradeable.sol";
    /**
     * @dev Required interface of an ERC721 compliant contract.
     */
    interface IERC721Upgradeable is IERC165Upgradeable {
        /**
         * @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
    // OpenZeppelin Contracts v4.4.1 (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 IERC721ReceiverUpgradeable {
        /**
         * @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
    // OpenZeppelin Contracts v4.4.1 (proxy/utils/Initializable.sol)
    pragma solidity ^0.8.0;
    import "../../utils/AddressUpgradeable.sol";
    /**
     * @dev This is a base contract to aid in writing upgradeable contracts, or any kind of contract that will be deployed
     * behind a proxy. Since a proxied contract can't have a constructor, it's common to move constructor logic to an
     * external initializer function, usually called `initialize`. It then becomes necessary to protect this initializer
     * function so it can only be called once. The {initializer} modifier provided by this contract will have this effect.
     *
     * TIP: To avoid leaving the proxy in an uninitialized state, the initializer function should be called as early as
     * possible by providing the encoded function call as the `_data` argument to {ERC1967Proxy-constructor}.
     *
     * CAUTION: When used with inheritance, manual care must be taken to not invoke a parent initializer twice, or to ensure
     * that all initializers are idempotent. This is not verified automatically as constructors are by Solidity.
     *
     * [CAUTION]
     * ====
     * Avoid leaving a contract uninitialized.
     *
     * An uninitialized contract can be taken over by an attacker. This applies to both a proxy and its implementation
     * contract, which may impact the proxy. To initialize the implementation contract, you can either invoke the
     * initializer manually, or you can include a constructor to automatically mark it as initialized when it is deployed:
     *
     * [.hljs-theme-light.nopadding]
     * ```
     * /// @custom:oz-upgrades-unsafe-allow constructor
     * constructor() initializer {}
     * ```
     * ====
     */
    abstract contract Initializable {
        /**
         * @dev Indicates that the contract has been initialized.
         */
        bool private _initialized;
        /**
         * @dev Indicates that the contract is in the process of being initialized.
         */
        bool private _initializing;
        /**
         * @dev Modifier to protect an initializer function from being invoked twice.
         */
        modifier initializer() {
            // If the contract is initializing we ignore whether _initialized is set in order to support multiple
            // inheritance patterns, but we only do this in the context of a constructor, because in other contexts the
            // contract may have been reentered.
            require(_initializing ? _isConstructor() : !_initialized, "Initializable: contract is already initialized");
            bool isTopLevelCall = !_initializing;
            if (isTopLevelCall) {
                _initializing = true;
                _initialized = true;
            }
            _;
            if (isTopLevelCall) {
                _initializing = false;
            }
        }
        /**
         * @dev Modifier to protect an initialization function so that it can only be invoked by functions with the
         * {initializer} modifier, directly or indirectly.
         */
        modifier onlyInitializing() {
            require(_initializing, "Initializable: contract is not initializing");
            _;
        }
        function _isConstructor() private view returns (bool) {
            return !AddressUpgradeable.isContract(address(this));
        }
    }
    // SPDX-License-Identifier: MIT
    // OpenZeppelin Contracts v4.4.1 (access/Ownable.sol)
    pragma solidity ^0.8.0;
    import "../utils/ContextUpgradeable.sol";
    import "../proxy/utils/Initializable.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 OwnableUpgradeable is Initializable, ContextUpgradeable {
        address private _owner;
        event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);
        /**
         * @dev Initializes the contract setting the deployer as the initial owner.
         */
        function __Ownable_init() internal onlyInitializing {
            __Context_init_unchained();
            __Ownable_init_unchained();
        }
        function __Ownable_init_unchained() internal onlyInitializing {
            _transferOwnership(_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 {
            _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);
        }
        uint256[49] private __gap;
    }