organized_contracts/17/170dd9a1301278ce0a9e87481d4aabf91ce0c7d994e1ffe9d07462f3c004112a/contract.json

{
  "language": "Solidity",
  "sources": {
    "contracts/PixelatedHorrors.sol": {
      "content": "// SPDX-License-Identifier: MIT \r\n\r\n// PIXELATED HORRORS. An art collective.\r\n\r\n\r\npragma solidity >=0.8.9 <0.9.0;\r\n\r\nimport 'erc721a/contracts/ERC721A.sol';\r\nimport '@openzeppelin/contracts/access/Ownable.sol';\r\nimport '@openzeppelin/contracts/utils/cryptography/MerkleProof.sol';\r\nimport '@openzeppelin/contracts/security/ReentrancyGuard.sol';\r\n\r\ncontract PixelatedHorrors is ERC721A, Ownable, ReentrancyGuard {\r\n\r\n  using Strings for uint256;\r\n\r\n  bytes32 public merkleRoot;\r\n  mapping(address => bool) public whitelistClaimed;\r\n\r\n  string public HORROR_SUMMON_PRICE = '0.0025 ETH UPON SALE LAUNCH, AFTER 10 MINUTES PRICE INCREASES TO 0.005 ETH.';\r\n  string public HORROR_TOTAL_MAX = '555 HORRORS';\r\n\r\n\r\n\r\n\r\n  string public uriPrefix = '';\r\n  string public uriSuffix = '.json';\r\n  string public hiddenMetadataUri;\r\n  \r\n  uint256 public cost;\r\n  uint256 public maxSupply;\r\n  uint256 public maxMintAmountPerTx;\r\n\r\n  bool public paused = true;\r\n  bool public whitelistMintEnabled = false;\r\n  bool public revealed = false;\r\n\r\n  constructor(\r\n    string memory _tokenName,\r\n    string memory _tokenSymbol,\r\n    uint256 _cost,\r\n    uint256 _maxSupply,\r\n    uint256 _maxMintAmountPerTx,\r\n    string memory _hiddenMetadataUri\r\n  ) ERC721A(_tokenName, _tokenSymbol) {\r\n    setCost(_cost);\r\n    maxSupply = _maxSupply;\r\n    setMaxMintAmountPerTx(_maxMintAmountPerTx);\r\n    setHiddenMetadataUri(_hiddenMetadataUri);\r\n  }\r\n\r\n  modifier mintCompliance(uint256 _mintAmount) {\r\n    require(_mintAmount > 0 && _mintAmount <= maxMintAmountPerTx, 'Invalid mint amount!');\r\n    require(totalSupply() + _mintAmount <= maxSupply, 'Sold out fren.');\r\n    _;\r\n  }\r\n\r\n  modifier mintPriceCompliance(uint256 _mintAmount) {\r\n    require(msg.value >= cost * _mintAmount, 'You dont have enough to mint.');\r\n    _;\r\n  }\r\n\r\n  function whitelistMint(uint256 _mintAmount, bytes32[] calldata _merkleProof) public payable mintCompliance(_mintAmount) mintPriceCompliance(_mintAmount) {\r\n    // Verify whitelist requirements\r\n    require(whitelistMintEnabled, 'The whitelist sale is not enabled!');\r\n    require(!whitelistClaimed[_msgSender()], 'Address already claimed!');\r\n    bytes32 leaf = keccak256(abi.encodePacked(_msgSender()));\r\n    require(MerkleProof.verify(_merkleProof, merkleRoot, leaf), 'Invalid proof!');\r\n\r\n    whitelistClaimed[_msgSender()] = true;\r\n    _safeMint(_msgSender(), _mintAmount);\r\n  }\r\n\r\n  function mint(uint256 _mintAmount) public payable mintCompliance(_mintAmount) mintPriceCompliance(_mintAmount) {\r\n    require(!paused, 'The contract is paused!');\r\n\r\n    _safeMint(_msgSender(), _mintAmount);\r\n  }\r\n  \r\n  function mintForAddress(uint256 _mintAmount, address _receiver) public onlyOwner {\r\n    _safeMint(_receiver, _mintAmount);\r\n  }\r\n\r\n  function walletOfOwner(address _owner) public view returns (uint256[] memory) {\r\n    uint256 ownerTokenCount = balanceOf(_owner);\r\n    uint256[] memory ownedTokenIds = new uint256[](ownerTokenCount);\r\n    uint256 currentTokenId = _startTokenId();\r\n    uint256 ownedTokenIndex = 0;\r\n    address latestOwnerAddress;\r\n\r\n    while (ownedTokenIndex < ownerTokenCount && currentTokenId < _currentIndex) {\r\n      TokenOwnership memory ownership = _ownerships[currentTokenId];\r\n\r\n      if (!ownership.burned) {\r\n        if (ownership.addr != address(0)) {\r\n          latestOwnerAddress = ownership.addr;\r\n        }\r\n\r\n        if (latestOwnerAddress == _owner) {\r\n          ownedTokenIds[ownedTokenIndex] = currentTokenId;\r\n\r\n          ownedTokenIndex++;\r\n        }\r\n      }\r\n\r\n      currentTokenId++;\r\n    }\r\n\r\n    return ownedTokenIds;\r\n  }\r\n\r\n  function _startTokenId() internal view virtual override returns (uint256) {\r\n    return 1;\r\n  }\r\n\r\n  function tokenURI(uint256 _tokenId) public view virtual override returns (string memory) {\r\n    require(_exists(_tokenId), 'ERC721Metadata: URI query for nonexistent token');\r\n\r\n    if (revealed == false) {\r\n      return hiddenMetadataUri;\r\n    }\r\n\r\n    string memory currentBaseURI = _baseURI();\r\n    return bytes(currentBaseURI).length > 0\r\n        ? string(abi.encodePacked(currentBaseURI, _tokenId.toString(), uriSuffix))\r\n        : '';\r\n  }\r\n\r\n  function setRevealed(bool _state) public onlyOwner {\r\n    revealed = _state;\r\n  }\r\n\r\n  function setCost(uint256 _cost) public onlyOwner {\r\n    cost = _cost;\r\n  }\r\n\r\n  function setMaxMintAmountPerTx(uint256 _maxMintAmountPerTx) public onlyOwner {\r\n    maxMintAmountPerTx = _maxMintAmountPerTx;\r\n  }\r\n\r\n  function setHiddenMetadataUri(string memory _hiddenMetadataUri) public onlyOwner {\r\n    hiddenMetadataUri = _hiddenMetadataUri;\r\n  }\r\n\r\n  function setUriPrefix(string memory _uriPrefix) public onlyOwner {\r\n    uriPrefix = _uriPrefix;\r\n  }\r\n\r\n  function setUriSuffix(string memory _uriSuffix) public onlyOwner {\r\n    uriSuffix = _uriSuffix;\r\n  }\r\n\r\n  function setPaused(bool _state) public onlyOwner {\r\n    paused = _state;\r\n  }\r\n\r\n  function setMerkleRoot(bytes32 _merkleRoot) public onlyOwner {\r\n    merkleRoot = _merkleRoot;\r\n  }\r\n\r\n  function setWhitelistMintEnabled(bool _state) public onlyOwner {\r\n    whitelistMintEnabled = _state;\r\n  }\r\n\r\n  function withdraw() public onlyOwner nonReentrant {\r\n    // This will transfer the remaining contract balance to the owner.\r\n    // Do not remove this otherwise you will not be able to withdraw the funds.\r\n    // =============================================================================\r\n    (bool os, ) = payable(owner()).call{value: address(this).balance}('');\r\n    require(os);\r\n    // =============================================================================\r\n  }\r\n\r\n  function _baseURI() internal view virtual override returns (string memory) {\r\n    return uriPrefix;\r\n  }\r\n}\r\n"
    },
    "erc721a/contracts/ERC721A.sol": {
      "content": "// SPDX-License-Identifier: MIT\n// Creator: Chiru Labs\n\npragma solidity ^0.8.4;\n\nimport '@openzeppelin/contracts/token/ERC721/IERC721.sol';\nimport '@openzeppelin/contracts/token/ERC721/IERC721Receiver.sol';\nimport '@openzeppelin/contracts/token/ERC721/extensions/IERC721Metadata.sol';\nimport '@openzeppelin/contracts/utils/Address.sol';\nimport '@openzeppelin/contracts/utils/Context.sol';\nimport '@openzeppelin/contracts/utils/Strings.sol';\nimport '@openzeppelin/contracts/utils/introspection/ERC165.sol';\n\nerror ApprovalCallerNotOwnerNorApproved();\nerror ApprovalQueryForNonexistentToken();\nerror ApproveToCaller();\nerror ApprovalToCurrentOwner();\nerror BalanceQueryForZeroAddress();\nerror MintToZeroAddress();\nerror MintZeroQuantity();\nerror OwnerQueryForNonexistentToken();\nerror TransferCallerNotOwnerNorApproved();\nerror TransferFromIncorrectOwner();\nerror TransferToNonERC721ReceiverImplementer();\nerror TransferToZeroAddress();\nerror URIQueryForNonexistentToken();\n\n/**\n * @dev Implementation of https://eips.ethereum.org/EIPS/eip-721[ERC721] Non-Fungible Token Standard, including\n * the Metadata extension. Built to optimize for lower gas during batch mints.\n *\n * Assumes serials are sequentially minted starting at _startTokenId() (defaults to 0, e.g. 0, 1, 2, 3..).\n *\n * Assumes that an owner cannot have more than 2**64 - 1 (max value of uint64) of supply.\n *\n * Assumes that the maximum token id cannot exceed 2**256 - 1 (max value of uint256).\n */\ncontract ERC721A is Context, ERC165, IERC721, IERC721Metadata {\n    using Address for address;\n    using Strings for uint256;\n\n    // Compiler will pack this into a single 256bit word.\n    struct TokenOwnership {\n        // The address of the owner.\n        address addr;\n        // Keeps track of the start time of ownership with minimal overhead for tokenomics.\n        uint64 startTimestamp;\n        // Whether the token has been burned.\n        bool burned;\n    }\n\n    // Compiler will pack this into a single 256bit word.\n    struct AddressData {\n        // Realistically, 2**64-1 is more than enough.\n        uint64 balance;\n        // Keeps track of mint count with minimal overhead for tokenomics.\n        uint64 numberMinted;\n        // Keeps track of burn count with minimal overhead for tokenomics.\n        uint64 numberBurned;\n        // For miscellaneous variable(s) pertaining to the address\n        // (e.g. number of whitelist mint slots used).\n        // If there are multiple variables, please pack them into a uint64.\n        uint64 aux;\n    }\n\n    // The tokenId of the next token to be minted.\n    uint256 internal _currentIndex;\n\n    // The number of tokens burned.\n    uint256 internal _burnCounter;\n\n    // Token name\n    string private _name;\n\n    // Token symbol\n    string private _symbol;\n\n    // Mapping from token ID to ownership details\n    // An empty struct value does not necessarily mean the token is unowned. See _ownershipOf implementation for details.\n    mapping(uint256 => TokenOwnership) internal _ownerships;\n\n    // Mapping owner address to address data\n    mapping(address => AddressData) private _addressData;\n\n    // Mapping from token ID to approved address\n    mapping(uint256 => address) private _tokenApprovals;\n\n    // Mapping from owner to operator approvals\n    mapping(address => mapping(address => bool)) private _operatorApprovals;\n\n    constructor(string memory name_, string memory symbol_) {\n        _name = name_;\n        _symbol = symbol_;\n        _currentIndex = _startTokenId();\n    }\n\n    /**\n     * To change the starting tokenId, please override this function.\n     */\n    function _startTokenId() internal view virtual returns (uint256) {\n        return 0;\n    }\n\n    /**\n     * @dev Burned tokens are calculated here, use _totalMinted() if you want to count just minted tokens.\n     */\n    function totalSupply() public view returns (uint256) {\n        // Counter underflow is impossible as _burnCounter cannot be incremented\n        // more than _currentIndex - _startTokenId() times\n        unchecked {\n            return _currentIndex - _burnCounter - _startTokenId();\n        }\n    }\n\n    /**\n     * Returns the total amount of tokens minted in the contract.\n     */\n    function _totalMinted() internal view returns (uint256) {\n        // Counter underflow is impossible as _currentIndex does not decrement,\n        // and it is initialized to _startTokenId()\n        unchecked {\n            return _currentIndex - _startTokenId();\n        }\n    }\n\n    /**\n     * @dev See {IERC165-supportsInterface}.\n     */\n    function supportsInterface(bytes4 interfaceId) public view virtual override(ERC165, IERC165) returns (bool) {\n        return\n            interfaceId == type(IERC721).interfaceId ||\n            interfaceId == type(IERC721Metadata).interfaceId ||\n            super.supportsInterface(interfaceId);\n    }\n\n    /**\n     * @dev See {IERC721-balanceOf}.\n     */\n    function balanceOf(address owner) public view override returns (uint256) {\n        if (owner == address(0)) revert BalanceQueryForZeroAddress();\n        return uint256(_addressData[owner].balance);\n    }\n\n    /**\n     * Returns the number of tokens minted by `owner`.\n     */\n    function _numberMinted(address owner) internal view returns (uint256) {\n        return uint256(_addressData[owner].numberMinted);\n    }\n\n    /**\n     * Returns the number of tokens burned by or on behalf of `owner`.\n     */\n    function _numberBurned(address owner) internal view returns (uint256) {\n        return uint256(_addressData[owner].numberBurned);\n    }\n\n    /**\n     * Returns the auxillary data for `owner`. (e.g. number of whitelist mint slots used).\n     */\n    function _getAux(address owner) internal view returns (uint64) {\n        return _addressData[owner].aux;\n    }\n\n    /**\n     * Sets the auxillary data for `owner`. (e.g. number of whitelist mint slots used).\n     * If there are multiple variables, please pack them into a uint64.\n     */\n    function _setAux(address owner, uint64 aux) internal {\n        _addressData[owner].aux = aux;\n    }\n\n    /**\n     * Gas spent here starts off proportional to the maximum mint batch size.\n     * It gradually moves to O(1) as tokens get transferred around in the collection over time.\n     */\n    function _ownershipOf(uint256 tokenId) internal view returns (TokenOwnership memory) {\n        uint256 curr = tokenId;\n\n        unchecked {\n            if (_startTokenId() <= curr && curr < _currentIndex) {\n                TokenOwnership memory ownership = _ownerships[curr];\n                if (!ownership.burned) {\n                    if (ownership.addr != address(0)) {\n                        return ownership;\n                    }\n                    // Invariant:\n                    // There will always be an ownership that has an address and is not burned\n                    // before an ownership that does not have an address and is not burned.\n                    // Hence, curr will not underflow.\n                    while (true) {\n                        curr--;\n                        ownership = _ownerships[curr];\n                        if (ownership.addr != address(0)) {\n                            return ownership;\n                        }\n                    }\n                }\n            }\n        }\n        revert OwnerQueryForNonexistentToken();\n    }\n\n    /**\n     * @dev See {IERC721-ownerOf}.\n     */\n    function ownerOf(uint256 tokenId) public view override returns (address) {\n        return _ownershipOf(tokenId).addr;\n    }\n\n    /**\n     * @dev See {IERC721Metadata-name}.\n     */\n    function name() public view virtual override returns (string memory) {\n        return _name;\n    }\n\n    /**\n     * @dev See {IERC721Metadata-symbol}.\n     */\n    function symbol() public view virtual override returns (string memory) {\n        return _symbol;\n    }\n\n    /**\n     * @dev See {IERC721Metadata-tokenURI}.\n     */\n    function tokenURI(uint256 tokenId) public view virtual override returns (string memory) {\n        if (!_exists(tokenId)) revert URIQueryForNonexistentToken();\n\n        string memory baseURI = _baseURI();\n        return bytes(baseURI).length != 0 ? string(abi.encodePacked(baseURI, tokenId.toString())) : '';\n    }\n\n    /**\n     * @dev Base URI for computing {tokenURI}. If set, the resulting URI for each\n     * token will be the concatenation of the `baseURI` and the `tokenId`. Empty\n     * by default, can be overriden in child contracts.\n     */\n    function _baseURI() internal view virtual returns (string memory) {\n        return '';\n    }\n\n    /**\n     * @dev See {IERC721-approve}.\n     */\n    function approve(address to, uint256 tokenId) public override {\n        address owner = ERC721A.ownerOf(tokenId);\n        if (to == owner) revert ApprovalToCurrentOwner();\n\n        if (_msgSender() != owner && !isApprovedForAll(owner, _msgSender())) {\n            revert ApprovalCallerNotOwnerNorApproved();\n        }\n\n        _approve(to, tokenId, owner);\n    }\n\n    /**\n     * @dev See {IERC721-getApproved}.\n     */\n    function getApproved(uint256 tokenId) public view override returns (address) {\n        if (!_exists(tokenId)) revert ApprovalQueryForNonexistentToken();\n\n        return _tokenApprovals[tokenId];\n    }\n\n    /**\n     * @dev See {IERC721-setApprovalForAll}.\n     */\n    function setApprovalForAll(address operator, bool approved) public virtual override {\n        if (operator == _msgSender()) revert ApproveToCaller();\n\n        _operatorApprovals[_msgSender()][operator] = approved;\n        emit ApprovalForAll(_msgSender(), operator, approved);\n    }\n\n    /**\n     * @dev See {IERC721-isApprovedForAll}.\n     */\n    function isApprovedForAll(address owner, address operator) public view virtual override returns (bool) {\n        return _operatorApprovals[owner][operator];\n    }\n\n    /**\n     * @dev See {IERC721-transferFrom}.\n     */\n    function transferFrom(\n        address from,\n        address to,\n        uint256 tokenId\n    ) public virtual override {\n        _transfer(from, to, tokenId);\n    }\n\n    /**\n     * @dev See {IERC721-safeTransferFrom}.\n     */\n    function safeTransferFrom(\n        address from,\n        address to,\n        uint256 tokenId\n    ) public virtual override {\n        safeTransferFrom(from, to, tokenId, '');\n    }\n\n    /**\n     * @dev See {IERC721-safeTransferFrom}.\n     */\n    function safeTransferFrom(\n        address from,\n        address to,\n        uint256 tokenId,\n        bytes memory _data\n    ) public virtual override {\n        _transfer(from, to, tokenId);\n        if (to.isContract() && !_checkContractOnERC721Received(from, to, tokenId, _data)) {\n            revert TransferToNonERC721ReceiverImplementer();\n        }\n    }\n\n    /**\n     * @dev Returns whether `tokenId` exists.\n     *\n     * Tokens can be managed by their owner or approved accounts via {approve} or {setApprovalForAll}.\n     *\n     * Tokens start existing when they are minted (`_mint`),\n     */\n    function _exists(uint256 tokenId) internal view returns (bool) {\n        return _startTokenId() <= tokenId && tokenId < _currentIndex && !_ownerships[tokenId].burned;\n    }\n\n    function _safeMint(address to, uint256 quantity) internal {\n        _safeMint(to, quantity, '');\n    }\n\n    /**\n     * @dev Safely mints `quantity` tokens and transfers them to `to`.\n     *\n     * Requirements:\n     *\n     * - If `to` refers to a smart contract, it must implement {IERC721Receiver-onERC721Received}, which is called for each safe transfer.\n     * - `quantity` must be greater than 0.\n     *\n     * Emits a {Transfer} event.\n     */\n    function _safeMint(\n        address to,\n        uint256 quantity,\n        bytes memory _data\n    ) internal {\n        _mint(to, quantity, _data, true);\n    }\n\n    /**\n     * @dev Mints `quantity` tokens and transfers them to `to`.\n     *\n     * Requirements:\n     *\n     * - `to` cannot be the zero address.\n     * - `quantity` must be greater than 0.\n     *\n     * Emits a {Transfer} event.\n     */\n    function _mint(\n        address to,\n        uint256 quantity,\n        bytes memory _data,\n        bool safe\n    ) internal {\n        uint256 startTokenId = _currentIndex;\n        if (to == address(0)) revert MintToZeroAddress();\n        if (quantity == 0) revert MintZeroQuantity();\n\n        _beforeTokenTransfers(address(0), to, startTokenId, quantity);\n\n        // Overflows are incredibly unrealistic.\n        // balance or numberMinted overflow if current value of either + quantity > 1.8e19 (2**64) - 1\n        // updatedIndex overflows if _currentIndex + quantity > 1.2e77 (2**256) - 1\n        unchecked {\n            _addressData[to].balance += uint64(quantity);\n            _addressData[to].numberMinted += uint64(quantity);\n\n            _ownerships[startTokenId].addr = to;\n            _ownerships[startTokenId].startTimestamp = uint64(block.timestamp);\n\n            uint256 updatedIndex = startTokenId;\n            uint256 end = updatedIndex + quantity;\n\n            if (safe && to.isContract()) {\n                do {\n                    emit Transfer(address(0), to, updatedIndex);\n                    if (!_checkContractOnERC721Received(address(0), to, updatedIndex++, _data)) {\n                        revert TransferToNonERC721ReceiverImplementer();\n                    }\n                } while (updatedIndex != end);\n                // Reentrancy protection\n                if (_currentIndex != startTokenId) revert();\n            } else {\n                do {\n                    emit Transfer(address(0), to, updatedIndex++);\n                } while (updatedIndex != end);\n            }\n            _currentIndex = updatedIndex;\n        }\n        _afterTokenTransfers(address(0), to, startTokenId, quantity);\n    }\n\n    /**\n     * @dev Transfers `tokenId` from `from` to `to`.\n     *\n     * Requirements:\n     *\n     * - `to` cannot be the zero address.\n     * - `tokenId` token must be owned by `from`.\n     *\n     * Emits a {Transfer} event.\n     */\n    function _transfer(\n        address from,\n        address to,\n        uint256 tokenId\n    ) private {\n        TokenOwnership memory prevOwnership = _ownershipOf(tokenId);\n\n        if (prevOwnership.addr != from) revert TransferFromIncorrectOwner();\n\n        bool isApprovedOrOwner = (_msgSender() == from ||\n            isApprovedForAll(from, _msgSender()) ||\n            getApproved(tokenId) == _msgSender());\n\n        if (!isApprovedOrOwner) revert TransferCallerNotOwnerNorApproved();\n        if (to == address(0)) revert TransferToZeroAddress();\n\n        _beforeTokenTransfers(from, to, tokenId, 1);\n\n        // Clear approvals from the previous owner\n        _approve(address(0), tokenId, from);\n\n        // Underflow of the sender's balance is impossible because we check for\n        // ownership above and the recipient's balance can't realistically overflow.\n        // Counter overflow is incredibly unrealistic as tokenId would have to be 2**256.\n        unchecked {\n            _addressData[from].balance -= 1;\n            _addressData[to].balance += 1;\n\n            TokenOwnership storage currSlot = _ownerships[tokenId];\n            currSlot.addr = to;\n            currSlot.startTimestamp = uint64(block.timestamp);\n\n            // If the ownership slot of tokenId+1 is not explicitly set, that means the transfer initiator owns it.\n            // Set the slot of tokenId+1 explicitly in storage to maintain correctness for ownerOf(tokenId+1) calls.\n            uint256 nextTokenId = tokenId + 1;\n            TokenOwnership storage nextSlot = _ownerships[nextTokenId];\n            if (nextSlot.addr == address(0)) {\n                // This will suffice for checking _exists(nextTokenId),\n                // as a burned slot cannot contain the zero address.\n                if (nextTokenId != _currentIndex) {\n                    nextSlot.addr = from;\n                    nextSlot.startTimestamp = prevOwnership.startTimestamp;\n                }\n            }\n        }\n\n        emit Transfer(from, to, tokenId);\n        _afterTokenTransfers(from, to, tokenId, 1);\n    }\n\n    /**\n     * @dev This is equivalent to _burn(tokenId, false)\n     */\n    function _burn(uint256 tokenId) internal virtual {\n        _burn(tokenId, false);\n    }\n\n    /**\n     * @dev Destroys `tokenId`.\n     * The approval is cleared when the token is burned.\n     *\n     * Requirements:\n     *\n     * - `tokenId` must exist.\n     *\n     * Emits a {Transfer} event.\n     */\n    function _burn(uint256 tokenId, bool approvalCheck) internal virtual {\n        TokenOwnership memory prevOwnership = _ownershipOf(tokenId);\n\n        address from = prevOwnership.addr;\n\n        if (approvalCheck) {\n            bool isApprovedOrOwner = (_msgSender() == from ||\n                isApprovedForAll(from, _msgSender()) ||\n                getApproved(tokenId) == _msgSender());\n\n            if (!isApprovedOrOwner) revert TransferCallerNotOwnerNorApproved();\n        }\n\n        _beforeTokenTransfers(from, address(0), tokenId, 1);\n\n        // Clear approvals from the previous owner\n        _approve(address(0), tokenId, from);\n\n        // Underflow of the sender's balance is impossible because we check for\n        // ownership above and the recipient's balance can't realistically overflow.\n        // Counter overflow is incredibly unrealistic as tokenId would have to be 2**256.\n        unchecked {\n            AddressData storage addressData = _addressData[from];\n            addressData.balance -= 1;\n            addressData.numberBurned += 1;\n\n            // Keep track of who burned the token, and the timestamp of burning.\n            TokenOwnership storage currSlot = _ownerships[tokenId];\n            currSlot.addr = from;\n            currSlot.startTimestamp = uint64(block.timestamp);\n            currSlot.burned = true;\n\n            // If the ownership slot of tokenId+1 is not explicitly set, that means the burn initiator owns it.\n            // Set the slot of tokenId+1 explicitly in storage to maintain correctness for ownerOf(tokenId+1) calls.\n            uint256 nextTokenId = tokenId + 1;\n            TokenOwnership storage nextSlot = _ownerships[nextTokenId];\n            if (nextSlot.addr == address(0)) {\n                // This will suffice for checking _exists(nextTokenId),\n                // as a burned slot cannot contain the zero address.\n                if (nextTokenId != _currentIndex) {\n                    nextSlot.addr = from;\n                    nextSlot.startTimestamp = prevOwnership.startTimestamp;\n                }\n            }\n        }\n\n        emit Transfer(from, address(0), tokenId);\n        _afterTokenTransfers(from, address(0), tokenId, 1);\n\n        // Overflow not possible, as _burnCounter cannot be exceed _currentIndex times.\n        unchecked {\n            _burnCounter++;\n        }\n    }\n\n    /**\n     * @dev Approve `to` to operate on `tokenId`\n     *\n     * Emits a {Approval} event.\n     */\n    function _approve(\n        address to,\n        uint256 tokenId,\n        address owner\n    ) private {\n        _tokenApprovals[tokenId] = to;\n        emit Approval(owner, to, tokenId);\n    }\n\n    /**\n     * @dev Internal function to invoke {IERC721Receiver-onERC721Received} on a target contract.\n     *\n     * @param from address representing the previous owner of the given token ID\n     * @param to target address that will receive the tokens\n     * @param tokenId uint256 ID of the token to be transferred\n     * @param _data bytes optional data to send along with the call\n     * @return bool whether the call correctly returned the expected magic value\n     */\n    function _checkContractOnERC721Received(\n        address from,\n        address to,\n        uint256 tokenId,\n        bytes memory _data\n    ) private returns (bool) {\n        try IERC721Receiver(to).onERC721Received(_msgSender(), from, tokenId, _data) returns (bytes4 retval) {\n            return retval == IERC721Receiver(to).onERC721Received.selector;\n        } catch (bytes memory reason) {\n            if (reason.length == 0) {\n                revert TransferToNonERC721ReceiverImplementer();\n            } else {\n                assembly {\n                    revert(add(32, reason), mload(reason))\n                }\n            }\n        }\n    }\n\n    /**\n     * @dev Hook that is called before a set of serially-ordered token ids are about to be transferred. This includes minting.\n     * And also called before burning one token.\n     *\n     * startTokenId - the first token id to be transferred\n     * quantity - the amount to be transferred\n     *\n     * Calling conditions:\n     *\n     * - When `from` and `to` are both non-zero, `from`'s `tokenId` will be\n     * transferred to `to`.\n     * - When `from` is zero, `tokenId` will be minted for `to`.\n     * - When `to` is zero, `tokenId` will be burned by `from`.\n     * - `from` and `to` are never both zero.\n     */\n    function _beforeTokenTransfers(\n        address from,\n        address to,\n        uint256 startTokenId,\n        uint256 quantity\n    ) internal virtual {}\n\n    /**\n     * @dev Hook that is called after a set of serially-ordered token ids have been transferred. This includes\n     * minting.\n     * And also called after one token has been burned.\n     *\n     * startTokenId - the first token id to be transferred\n     * quantity - the amount to be transferred\n     *\n     * Calling conditions:\n     *\n     * - When `from` and `to` are both non-zero, `from`'s `tokenId` has been\n     * transferred to `to`.\n     * - When `from` is zero, `tokenId` has been minted for `to`.\n     * - When `to` is zero, `tokenId` has been burned by `from`.\n     * - `from` and `to` are never both zero.\n     */\n    function _afterTokenTransfers(\n        address from,\n        address to,\n        uint256 startTokenId,\n        uint256 quantity\n    ) internal virtual {}\n}\n"
    },
    "@openzeppelin/contracts/access/Ownable.sol": {
      "content": "// SPDX-License-Identifier: MIT\n// OpenZeppelin Contracts v4.4.1 (access/Ownable.sol)\n\npragma solidity ^0.8.0;\n\nimport \"../utils/Context.sol\";\n\n/**\n * @dev Contract module which provides a basic access control mechanism, where\n * there is an account (an owner) that can be granted exclusive access to\n * specific functions.\n *\n * By default, the owner account will be the one that deploys the contract. This\n * can later be changed with {transferOwnership}.\n *\n * This module is used through inheritance. It will make available the modifier\n * `onlyOwner`, which can be applied to your functions to restrict their use to\n * the owner.\n */\nabstract contract Ownable is Context {\n    address private _owner;\n\n    event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);\n\n    /**\n     * @dev Initializes the contract setting the deployer as the initial owner.\n     */\n    constructor() {\n        _transferOwnership(_msgSender());\n    }\n\n    /**\n     * @dev Returns the address of the current owner.\n     */\n    function owner() public view virtual returns (address) {\n        return _owner;\n    }\n\n    /**\n     * @dev Throws if called by any account other than the owner.\n     */\n    modifier onlyOwner() {\n        require(owner() == _msgSender(), \"Ownable: caller is not the owner\");\n        _;\n    }\n\n    /**\n     * @dev Leaves the contract without owner. It will not be possible to call\n     * `onlyOwner` functions anymore. Can only be called by the current owner.\n     *\n     * NOTE: Renouncing ownership will leave the contract without an owner,\n     * thereby removing any functionality that is only available to the owner.\n     */\n    function renounceOwnership() public virtual onlyOwner {\n        _transferOwnership(address(0));\n    }\n\n    /**\n     * @dev Transfers ownership of the contract to a new account (`newOwner`).\n     * Can only be called by the current owner.\n     */\n    function transferOwnership(address newOwner) public virtual onlyOwner {\n        require(newOwner != address(0), \"Ownable: new owner is the zero address\");\n        _transferOwnership(newOwner);\n    }\n\n    /**\n     * @dev Transfers ownership of the contract to a new account (`newOwner`).\n     * Internal function without access restriction.\n     */\n    function _transferOwnership(address newOwner) internal virtual {\n        address oldOwner = _owner;\n        _owner = newOwner;\n        emit OwnershipTransferred(oldOwner, newOwner);\n    }\n}\n"
    },
    "@openzeppelin/contracts/utils/cryptography/MerkleProof.sol": {
      "content": "// SPDX-License-Identifier: MIT\n// OpenZeppelin Contracts (last updated v4.5.0) (utils/cryptography/MerkleProof.sol)\n\npragma solidity ^0.8.0;\n\n/**\n * @dev These functions deal with verification of Merkle Trees proofs.\n *\n * The proofs can be generated using the JavaScript library\n * https://github.com/miguelmota/merkletreejs[merkletreejs].\n * Note: the hashing algorithm should be keccak256 and pair sorting should be enabled.\n *\n * See `test/utils/cryptography/MerkleProof.test.js` for some examples.\n */\nlibrary MerkleProof {\n    /**\n     * @dev Returns true if a `leaf` can be proved to be a part of a Merkle tree\n     * defined by `root`. For this, a `proof` must be provided, containing\n     * sibling hashes on the branch from the leaf to the root of the tree. Each\n     * pair of leaves and each pair of pre-images are assumed to be sorted.\n     */\n    function verify(\n        bytes32[] memory proof,\n        bytes32 root,\n        bytes32 leaf\n    ) internal pure returns (bool) {\n        return processProof(proof, leaf) == root;\n    }\n\n    /**\n     * @dev Returns the rebuilt hash obtained by traversing a Merklee tree up\n     * from `leaf` using `proof`. A `proof` is valid if and only if the rebuilt\n     * hash matches the root of the tree. When processing the proof, the pairs\n     * of leafs & pre-images are assumed to be sorted.\n     *\n     * _Available since v4.4._\n     */\n    function processProof(bytes32[] memory proof, bytes32 leaf) internal pure returns (bytes32) {\n        bytes32 computedHash = leaf;\n        for (uint256 i = 0; i < proof.length; i++) {\n            bytes32 proofElement = proof[i];\n            if (computedHash <= proofElement) {\n                // Hash(current computed hash + current element of the proof)\n                computedHash = _efficientHash(computedHash, proofElement);\n            } else {\n                // Hash(current element of the proof + current computed hash)\n                computedHash = _efficientHash(proofElement, computedHash);\n            }\n        }\n        return computedHash;\n    }\n\n    function _efficientHash(bytes32 a, bytes32 b) private pure returns (bytes32 value) {\n        assembly {\n            mstore(0x00, a)\n            mstore(0x20, b)\n            value := keccak256(0x00, 0x40)\n        }\n    }\n}\n"
    },
    "@openzeppelin/contracts/security/ReentrancyGuard.sol": {
      "content": "// SPDX-License-Identifier: MIT\n// OpenZeppelin Contracts v4.4.1 (security/ReentrancyGuard.sol)\n\npragma solidity ^0.8.0;\n\n/**\n * @dev Contract module that helps prevent reentrant calls to a function.\n *\n * Inheriting from `ReentrancyGuard` will make the {nonReentrant} modifier\n * available, which can be applied to functions to make sure there are no nested\n * (reentrant) calls to them.\n *\n * Note that because there is a single `nonReentrant` guard, functions marked as\n * `nonReentrant` may not call one another. This can be worked around by making\n * those functions `private`, and then adding `external` `nonReentrant` entry\n * points to them.\n *\n * TIP: If you would like to learn more about reentrancy and alternative ways\n * to protect against it, check out our blog post\n * https://blog.openzeppelin.com/reentrancy-after-istanbul/[Reentrancy After Istanbul].\n */\nabstract contract ReentrancyGuard {\n    // Booleans are more expensive than uint256 or any type that takes up a full\n    // word because each write operation emits an extra SLOAD to first read the\n    // slot's contents, replace the bits taken up by the boolean, and then write\n    // back. This is the compiler's defense against contract upgrades and\n    // pointer aliasing, and it cannot be disabled.\n\n    // The values being non-zero value makes deployment a bit more expensive,\n    // but in exchange the refund on every call to nonReentrant will be lower in\n    // amount. Since refunds are capped to a percentage of the total\n    // transaction's gas, it is best to keep them low in cases like this one, to\n    // increase the likelihood of the full refund coming into effect.\n    uint256 private constant _NOT_ENTERED = 1;\n    uint256 private constant _ENTERED = 2;\n\n    uint256 private _status;\n\n    constructor() {\n        _status = _NOT_ENTERED;\n    }\n\n    /**\n     * @dev Prevents a contract from calling itself, directly or indirectly.\n     * Calling a `nonReentrant` function from another `nonReentrant`\n     * function is not supported. It is possible to prevent this from happening\n     * by making the `nonReentrant` function external, and making it call a\n     * `private` function that does the actual work.\n     */\n    modifier nonReentrant() {\n        // On the first call to nonReentrant, _notEntered will be true\n        require(_status != _ENTERED, \"ReentrancyGuard: reentrant call\");\n\n        // Any calls to nonReentrant after this point will fail\n        _status = _ENTERED;\n\n        _;\n\n        // By storing the original value once again, a refund is triggered (see\n        // https://eips.ethereum.org/EIPS/eip-2200)\n        _status = _NOT_ENTERED;\n    }\n}\n"
    },
    "@openzeppelin/contracts/token/ERC721/IERC721.sol": {
      "content": "// SPDX-License-Identifier: MIT\n// OpenZeppelin Contracts v4.4.1 (token/ERC721/IERC721.sol)\n\npragma solidity ^0.8.0;\n\nimport \"../../utils/introspection/IERC165.sol\";\n\n/**\n * @dev Required interface of an ERC721 compliant contract.\n */\ninterface IERC721 is IERC165 {\n    /**\n     * @dev Emitted when `tokenId` token is transferred from `from` to `to`.\n     */\n    event Transfer(address indexed from, address indexed to, uint256 indexed tokenId);\n\n    /**\n     * @dev Emitted when `owner` enables `approved` to manage the `tokenId` token.\n     */\n    event Approval(address indexed owner, address indexed approved, uint256 indexed tokenId);\n\n    /**\n     * @dev Emitted when `owner` enables or disables (`approved`) `operator` to manage all of its assets.\n     */\n    event ApprovalForAll(address indexed owner, address indexed operator, bool approved);\n\n    /**\n     * @dev Returns the number of tokens in ``owner``'s account.\n     */\n    function balanceOf(address owner) external view returns (uint256 balance);\n\n    /**\n     * @dev Returns the owner of the `tokenId` token.\n     *\n     * Requirements:\n     *\n     * - `tokenId` must exist.\n     */\n    function ownerOf(uint256 tokenId) external view returns (address owner);\n\n    /**\n     * @dev Safely transfers `tokenId` token from `from` to `to`, checking first that contract recipients\n     * are aware of the ERC721 protocol to prevent tokens from being forever locked.\n     *\n     * Requirements:\n     *\n     * - `from` cannot be the zero address.\n     * - `to` cannot be the zero address.\n     * - `tokenId` token must exist and be owned by `from`.\n     * - If the caller is not `from`, it must be have been allowed to move this token by either {approve} or {setApprovalForAll}.\n     * - If `to` refers to a smart contract, it must implement {IERC721Receiver-onERC721Received}, which is called upon a safe transfer.\n     *\n     * Emits a {Transfer} event.\n     */\n    function safeTransferFrom(\n        address from,\n        address to,\n        uint256 tokenId\n    ) external;\n\n    /**\n     * @dev Transfers `tokenId` token from `from` to `to`.\n     *\n     * WARNING: Usage of this method is discouraged, use {safeTransferFrom} whenever possible.\n     *\n     * Requirements:\n     *\n     * - `from` cannot be the zero address.\n     * - `to` cannot be the zero address.\n     * - `tokenId` token must be owned by `from`.\n     * - If the caller is not `from`, it must be approved to move this token by either {approve} or {setApprovalForAll}.\n     *\n     * Emits a {Transfer} event.\n     */\n    function transferFrom(\n        address from,\n        address to,\n        uint256 tokenId\n    ) external;\n\n    /**\n     * @dev Gives permission to `to` to transfer `tokenId` token to another account.\n     * The approval is cleared when the token is transferred.\n     *\n     * Only a single account can be approved at a time, so approving the zero address clears previous approvals.\n     *\n     * Requirements:\n     *\n     * - The caller must own the token or be an approved operator.\n     * - `tokenId` must exist.\n     *\n     * Emits an {Approval} event.\n     */\n    function approve(address to, uint256 tokenId) external;\n\n    /**\n     * @dev Returns the account approved for `tokenId` token.\n     *\n     * Requirements:\n     *\n     * - `tokenId` must exist.\n     */\n    function getApproved(uint256 tokenId) external view returns (address operator);\n\n    /**\n     * @dev Approve or remove `operator` as an operator for the caller.\n     * Operators can call {transferFrom} or {safeTransferFrom} for any token owned by the caller.\n     *\n     * Requirements:\n     *\n     * - The `operator` cannot be the caller.\n     *\n     * Emits an {ApprovalForAll} event.\n     */\n    function setApprovalForAll(address operator, bool _approved) external;\n\n    /**\n     * @dev Returns if the `operator` is allowed to manage all of the assets of `owner`.\n     *\n     * See {setApprovalForAll}\n     */\n    function isApprovedForAll(address owner, address operator) external view returns (bool);\n\n    /**\n     * @dev Safely transfers `tokenId` token from `from` to `to`.\n     *\n     * Requirements:\n     *\n     * - `from` cannot be the zero address.\n     * - `to` cannot be the zero address.\n     * - `tokenId` token must exist and be owned by `from`.\n     * - If the caller is not `from`, it must be approved to move this token by either {approve} or {setApprovalForAll}.\n     * - If `to` refers to a smart contract, it must implement {IERC721Receiver-onERC721Received}, which is called upon a safe transfer.\n     *\n     * Emits a {Transfer} event.\n     */\n    function safeTransferFrom(\n        address from,\n        address to,\n        uint256 tokenId,\n        bytes calldata data\n    ) external;\n}\n"
    },
    "@openzeppelin/contracts/token/ERC721/IERC721Receiver.sol": {
      "content": "// SPDX-License-Identifier: MIT\n// OpenZeppelin Contracts v4.4.1 (token/ERC721/IERC721Receiver.sol)\n\npragma solidity ^0.8.0;\n\n/**\n * @title ERC721 token receiver interface\n * @dev Interface for any contract that wants to support safeTransfers\n * from ERC721 asset contracts.\n */\ninterface IERC721Receiver {\n    /**\n     * @dev Whenever an {IERC721} `tokenId` token is transferred to this contract via {IERC721-safeTransferFrom}\n     * by `operator` from `from`, this function is called.\n     *\n     * It must return its Solidity selector to confirm the token transfer.\n     * If any other value is returned or the interface is not implemented by the recipient, the transfer will be reverted.\n     *\n     * The selector can be obtained in Solidity with `IERC721.onERC721Received.selector`.\n     */\n    function onERC721Received(\n        address operator,\n        address from,\n        uint256 tokenId,\n        bytes calldata data\n    ) external returns (bytes4);\n}\n"
    },
    "@openzeppelin/contracts/token/ERC721/extensions/IERC721Metadata.sol": {
      "content": "// SPDX-License-Identifier: MIT\n// OpenZeppelin Contracts v4.4.1 (token/ERC721/extensions/IERC721Metadata.sol)\n\npragma solidity ^0.8.0;\n\nimport \"../IERC721.sol\";\n\n/**\n * @title ERC-721 Non-Fungible Token Standard, optional metadata extension\n * @dev See https://eips.ethereum.org/EIPS/eip-721\n */\ninterface IERC721Metadata is IERC721 {\n    /**\n     * @dev Returns the token collection name.\n     */\n    function name() external view returns (string memory);\n\n    /**\n     * @dev Returns the token collection symbol.\n     */\n    function symbol() external view returns (string memory);\n\n    /**\n     * @dev Returns the Uniform Resource Identifier (URI) for `tokenId` token.\n     */\n    function tokenURI(uint256 tokenId) external view returns (string memory);\n}\n"
    },
    "@openzeppelin/contracts/utils/Address.sol": {
      "content": "// SPDX-License-Identifier: MIT\n// OpenZeppelin Contracts (last updated v4.5.0) (utils/Address.sol)\n\npragma solidity ^0.8.1;\n\n/**\n * @dev Collection of functions related to the address type\n */\nlibrary Address {\n    /**\n     * @dev Returns true if `account` is a contract.\n     *\n     * [IMPORTANT]\n     * ====\n     * It is unsafe to assume that an address for which this function returns\n     * false is an externally-owned account (EOA) and not a contract.\n     *\n     * Among others, `isContract` will return false for the following\n     * types of addresses:\n     *\n     *  - an externally-owned account\n     *  - a contract in construction\n     *  - an address where a contract will be created\n     *  - an address where a contract lived, but was destroyed\n     * ====\n     *\n     * [IMPORTANT]\n     * ====\n     * You shouldn't rely on `isContract` to protect against flash loan attacks!\n     *\n     * Preventing calls from contracts is highly discouraged. It breaks composability, breaks support for smart wallets\n     * like Gnosis Safe, and does not provide security since it can be circumvented by calling from a contract\n     * constructor.\n     * ====\n     */\n    function isContract(address account) internal view returns (bool) {\n        // This method relies on extcodesize/address.code.length, which returns 0\n        // for contracts in construction, since the code is only stored at the end\n        // of the constructor execution.\n\n        return account.code.length > 0;\n    }\n\n    /**\n     * @dev Replacement for Solidity's `transfer`: sends `amount` wei to\n     * `recipient`, forwarding all available gas and reverting on errors.\n     *\n     * https://eips.ethereum.org/EIPS/eip-1884[EIP1884] increases the gas cost\n     * of certain opcodes, possibly making contracts go over the 2300 gas limit\n     * imposed by `transfer`, making them unable to receive funds via\n     * `transfer`. {sendValue} removes this limitation.\n     *\n     * https://diligence.consensys.net/posts/2019/09/stop-using-soliditys-transfer-now/[Learn more].\n     *\n     * IMPORTANT: because control is transferred to `recipient`, care must be\n     * taken to not create reentrancy vulnerabilities. Consider using\n     * {ReentrancyGuard} or the\n     * https://solidity.readthedocs.io/en/v0.5.11/security-considerations.html#use-the-checks-effects-interactions-pattern[checks-effects-interactions pattern].\n     */\n    function sendValue(address payable recipient, uint256 amount) internal {\n        require(address(this).balance >= amount, \"Address: insufficient balance\");\n\n        (bool success, ) = recipient.call{value: amount}(\"\");\n        require(success, \"Address: unable to send value, recipient may have reverted\");\n    }\n\n    /**\n     * @dev Performs a Solidity function call using a low level `call`. A\n     * plain `call` is an unsafe replacement for a function call: use this\n     * function instead.\n     *\n     * If `target` reverts with a revert reason, it is bubbled up by this\n     * function (like regular Solidity function calls).\n     *\n     * Returns the raw returned data. To convert to the expected return value,\n     * use https://solidity.readthedocs.io/en/latest/units-and-global-variables.html?highlight=abi.decode#abi-encoding-and-decoding-functions[`abi.decode`].\n     *\n     * Requirements:\n     *\n     * - `target` must be a contract.\n     * - calling `target` with `data` must not revert.\n     *\n     * _Available since v3.1._\n     */\n    function functionCall(address target, bytes memory data) internal returns (bytes memory) {\n        return functionCall(target, data, \"Address: low-level call failed\");\n    }\n\n    /**\n     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`], but with\n     * `errorMessage` as a fallback revert reason when `target` reverts.\n     *\n     * _Available since v3.1._\n     */\n    function functionCall(\n        address target,\n        bytes memory data,\n        string memory errorMessage\n    ) internal returns (bytes memory) {\n        return functionCallWithValue(target, data, 0, errorMessage);\n    }\n\n    /**\n     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],\n     * but also transferring `value` wei to `target`.\n     *\n     * Requirements:\n     *\n     * - the calling contract must have an ETH balance of at least `value`.\n     * - the called Solidity function must be `payable`.\n     *\n     * _Available since v3.1._\n     */\n    function functionCallWithValue(\n        address target,\n        bytes memory data,\n        uint256 value\n    ) internal returns (bytes memory) {\n        return functionCallWithValue(target, data, value, \"Address: low-level call with value failed\");\n    }\n\n    /**\n     * @dev Same as {xref-Address-functionCallWithValue-address-bytes-uint256-}[`functionCallWithValue`], but\n     * with `errorMessage` as a fallback revert reason when `target` reverts.\n     *\n     * _Available since v3.1._\n     */\n    function functionCallWithValue(\n        address target,\n        bytes memory data,\n        uint256 value,\n        string memory errorMessage\n    ) internal returns (bytes memory) {\n        require(address(this).balance >= value, \"Address: insufficient balance for call\");\n        require(isContract(target), \"Address: call to non-contract\");\n\n        (bool success, bytes memory returndata) = target.call{value: value}(data);\n        return verifyCallResult(success, returndata, errorMessage);\n    }\n\n    /**\n     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],\n     * but performing a static call.\n     *\n     * _Available since v3.3._\n     */\n    function functionStaticCall(address target, bytes memory data) internal view returns (bytes memory) {\n        return functionStaticCall(target, data, \"Address: low-level static call failed\");\n    }\n\n    /**\n     * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],\n     * but performing a static call.\n     *\n     * _Available since v3.3._\n     */\n    function functionStaticCall(\n        address target,\n        bytes memory data,\n        string memory errorMessage\n    ) internal view returns (bytes memory) {\n        require(isContract(target), \"Address: static call to non-contract\");\n\n        (bool success, bytes memory returndata) = target.staticcall(data);\n        return verifyCallResult(success, returndata, errorMessage);\n    }\n\n    /**\n     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],\n     * but performing a delegate call.\n     *\n     * _Available since v3.4._\n     */\n    function functionDelegateCall(address target, bytes memory data) internal returns (bytes memory) {\n        return functionDelegateCall(target, data, \"Address: low-level delegate call failed\");\n    }\n\n    /**\n     * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],\n     * but performing a delegate call.\n     *\n     * _Available since v3.4._\n     */\n    function functionDelegateCall(\n        address target,\n        bytes memory data,\n        string memory errorMessage\n    ) internal returns (bytes memory) {\n        require(isContract(target), \"Address: delegate call to non-contract\");\n\n        (bool success, bytes memory returndata) = target.delegatecall(data);\n        return verifyCallResult(success, returndata, errorMessage);\n    }\n\n    /**\n     * @dev Tool to verifies that a low level call was successful, and revert if it wasn't, either by bubbling the\n     * revert reason using the provided one.\n     *\n     * _Available since v4.3._\n     */\n    function verifyCallResult(\n        bool success,\n        bytes memory returndata,\n        string memory errorMessage\n    ) internal pure returns (bytes memory) {\n        if (success) {\n            return returndata;\n        } else {\n            // Look for revert reason and bubble it up if present\n            if (returndata.length > 0) {\n                // The easiest way to bubble the revert reason is using memory via assembly\n\n                assembly {\n                    let returndata_size := mload(returndata)\n                    revert(add(32, returndata), returndata_size)\n                }\n            } else {\n                revert(errorMessage);\n            }\n        }\n    }\n}\n"
    },
    "@openzeppelin/contracts/utils/Context.sol": {
      "content": "// SPDX-License-Identifier: MIT\n// OpenZeppelin Contracts v4.4.1 (utils/Context.sol)\n\npragma solidity ^0.8.0;\n\n/**\n * @dev Provides information about the current execution context, including the\n * sender of the transaction and its data. While these are generally available\n * via msg.sender and msg.data, they should not be accessed in such a direct\n * manner, since when dealing with meta-transactions the account sending and\n * paying for execution may not be the actual sender (as far as an application\n * is concerned).\n *\n * This contract is only required for intermediate, library-like contracts.\n */\nabstract contract Context {\n    function _msgSender() internal view virtual returns (address) {\n        return msg.sender;\n    }\n\n    function _msgData() internal view virtual returns (bytes calldata) {\n        return msg.data;\n    }\n}\n"
    },
    "@openzeppelin/contracts/utils/Strings.sol": {
      "content": "// SPDX-License-Identifier: MIT\n// OpenZeppelin Contracts v4.4.1 (utils/Strings.sol)\n\npragma solidity ^0.8.0;\n\n/**\n * @dev String operations.\n */\nlibrary Strings {\n    bytes16 private constant _HEX_SYMBOLS = \"0123456789abcdef\";\n\n    /**\n     * @dev Converts a `uint256` to its ASCII `string` decimal representation.\n     */\n    function toString(uint256 value) internal pure returns (string memory) {\n        // Inspired by OraclizeAPI's implementation - MIT licence\n        // https://github.com/oraclize/ethereum-api/blob/b42146b063c7d6ee1358846c198246239e9360e8/oraclizeAPI_0.4.25.sol\n\n        if (value == 0) {\n            return \"0\";\n        }\n        uint256 temp = value;\n        uint256 digits;\n        while (temp != 0) {\n            digits++;\n            temp /= 10;\n        }\n        bytes memory buffer = new bytes(digits);\n        while (value != 0) {\n            digits -= 1;\n            buffer[digits] = bytes1(uint8(48 + uint256(value % 10)));\n            value /= 10;\n        }\n        return string(buffer);\n    }\n\n    /**\n     * @dev Converts a `uint256` to its ASCII `string` hexadecimal representation.\n     */\n    function toHexString(uint256 value) internal pure returns (string memory) {\n        if (value == 0) {\n            return \"0x00\";\n        }\n        uint256 temp = value;\n        uint256 length = 0;\n        while (temp != 0) {\n            length++;\n            temp >>= 8;\n        }\n        return toHexString(value, length);\n    }\n\n    /**\n     * @dev Converts a `uint256` to its ASCII `string` hexadecimal representation with fixed length.\n     */\n    function toHexString(uint256 value, uint256 length) internal pure returns (string memory) {\n        bytes memory buffer = new bytes(2 * length + 2);\n        buffer[0] = \"0\";\n        buffer[1] = \"x\";\n        for (uint256 i = 2 * length + 1; i > 1; --i) {\n            buffer[i] = _HEX_SYMBOLS[value & 0xf];\n            value >>= 4;\n        }\n        require(value == 0, \"Strings: hex length insufficient\");\n        return string(buffer);\n    }\n}\n"
    },
    "@openzeppelin/contracts/utils/introspection/ERC165.sol": {
      "content": "// SPDX-License-Identifier: MIT\n// OpenZeppelin Contracts v4.4.1 (utils/introspection/ERC165.sol)\n\npragma solidity ^0.8.0;\n\nimport \"./IERC165.sol\";\n\n/**\n * @dev Implementation of the {IERC165} interface.\n *\n * Contracts that want to implement ERC165 should inherit from this contract and override {supportsInterface} to check\n * for the additional interface id that will be supported. For example:\n *\n * ```solidity\n * function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) {\n *     return interfaceId == type(MyInterface).interfaceId || super.supportsInterface(interfaceId);\n * }\n * ```\n *\n * Alternatively, {ERC165Storage} provides an easier to use but more expensive implementation.\n */\nabstract contract ERC165 is IERC165 {\n    /**\n     * @dev See {IERC165-supportsInterface}.\n     */\n    function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) {\n        return interfaceId == type(IERC165).interfaceId;\n    }\n}\n"
    },
    "@openzeppelin/contracts/utils/introspection/IERC165.sol": {
      "content": "// SPDX-License-Identifier: MIT\n// OpenZeppelin Contracts v4.4.1 (utils/introspection/IERC165.sol)\n\npragma solidity ^0.8.0;\n\n/**\n * @dev Interface of the ERC165 standard, as defined in the\n * https://eips.ethereum.org/EIPS/eip-165[EIP].\n *\n * Implementers can declare support of contract interfaces, which can then be\n * queried by others ({ERC165Checker}).\n *\n * For an implementation, see {ERC165}.\n */\ninterface IERC165 {\n    /**\n     * @dev Returns true if this contract implements the interface defined by\n     * `interfaceId`. See the corresponding\n     * https://eips.ethereum.org/EIPS/eip-165#how-interfaces-are-identified[EIP section]\n     * to learn more about how these ids are created.\n     *\n     * This function call must use less than 30 000 gas.\n     */\n    function supportsInterface(bytes4 interfaceId) external view returns (bool);\n}\n"
    }
  },
  "settings": {
    "optimizer": {
      "enabled": true,
      "runs": 200
    },
    "outputSelection": {
      "*": {
        "*": [
          "evm.bytecode",
          "evm.deployedBytecode",
          "devdoc",
          "userdoc",
          "metadata",
          "abi"
        ]
      }
    },
    "libraries": {}
  }
}