contract ERC721Mintable is ERC721Upgradeable {

    constructor () public {
        __ERC721_init("ERC 721", "NFT");
    }

    /**
     * @dev See {ERC721-_mint}.
     */
    function mint(address to, uint256 tokenId) public {
        _mint(to, tokenId);
    }

    /**
     * @dev See {ERC721-_burn}.
     */
    function burn(uint256 tokenId) public {
        _burn(tokenId);
    }
}
/**
 * @dev Extension of {ERC721} for Minting/Burning
 */
function mint(address to, uint256 tokenId) public {
    _mint(to, tokenId);
}

/**
 * @dev See {ERC721-_mint}.
 */