contract Token is ERC721TokenWithData {

	string metadataUrlPrefix = "https://metadata.cryptoassault.io/unit/";

	/**
	* @dev Returns an URI for a given token ID
	* Throws if the token ID does not exist. May return an empty string.
	* @param _tokenId uint256 ID of the token to query
	*/
	function tokenURI(uint256 _tokenId) public view returns (string) {
		require(exists(_tokenId));
		return Strings.strConcat(metadataUrlPrefix, Strings.uint2str(_tokenId));
	}

	function setMetadataUrlPrefix(string _metadataUrlPrefix) public onlyOwner
	{
		metadataUrlPrefix = _metadataUrlPrefix;
	}
}
function tokenURI(uint256 _tokenId) public view returns (string) {
	require(exists(_tokenId));
	return Strings.strConcat(metadataUrlPrefix, Strings.uint2str(_tokenId));
}

/**
 	* @dev Returns an URI for a given token ID
 	* Throws if the token ID does not exist. May return an empty string.
 	* @param _tokenId uint256 ID of the token to query
 	*/