pragma solidity ^0.6.0; import "./ERC721.sol"; import "../../utils/Pausable.sol"; /** * @dev ERC721 token with pausable token transfers, minting and burning. * * Useful for scenarios such as preventing trades until the end of an evaluation * period, or having an emergency switch for freezing all token transfers in the * event of a large bug. */ abstract contract ERC721Pausable is ERC721, Pausable { /** * @dev See {ERC721-_beforeTokenTransfer}. * * Requirements: * * - the contract must not be paused. */ function _beforeTokenTransfer(address from, address to, uint256 tokenId) internal virtual override { super._beforeTokenTransfer(from, to, tokenId); require(!paused(), "ERC721Pausable: token transfer while paused"); } }