/**
 *  @title Interface for contracts conforming to ERC-721: Non-Fungible Tokens
 *  @author Dieter Shirley <dete@axiomzen.co> (https://github.com/dete) 
 *  This code was taken from https://github.com/dapperlabs at 
 *  https://github.com/dapperlabs/cryptokitties-bounty and is NOT kleros code.
 */
pragma solidity ^0.4.18;


/// @title Interface for contracts conforming to ERC-721: Non-Fungible Tokens
/// @author Dieter Shirley <dete@axiomzen.co> (https://github.com/dete)
contract ERC721 {
    function implementsERC721() public pure returns (bool);
    function totalSupply() public view returns (uint256 total);
    function balanceOf(address _owner) public view returns (uint256 balance);
    function ownerOf(uint256 _tokenId) public view returns (address owner);
    function approve(address _to, uint256 _tokenId) public;
    function transferFrom(address _from, address _to, uint256 _tokenId) public;
    function transfer(address _to, uint256 _tokenId) public;
    event Transfer(address indexed from, address indexed to, uint256 indexed tokenId);
    event Approval(address indexed owner, address indexed approved, uint256 indexed tokenId);

    // Optional
    // function name() public view returns (string name);
    // function symbol() public view returns (string symbol);
    // function tokenOfOwnerByIndex(address _owner, uint256 _index) external view returns (uint256 tokenId);
    // function tokenMetadata(uint256 _tokenId) public view returns (string infoUrl);
}