library String {
    /**
     * @dev Convert uint to string.
     * @param _i - uint256 to be converted to string.
     * @return _uintAsString
     */
    function uint2str(uint256 _i)
        internal
        pure
        returns (string memory _uintAsString)
    {
        if (_i == 0) {
            return "0";
        }
        uint256 j = _i;
        uint256 len;
        while (j != 0) {
            len++;
            j /= 10;
        }
        bytes memory bstr = new bytes(len);
        uint256 k = len;
        while (_i != 0) {
            k = k - 1;
            uint8 temp = (48 + uint8(_i - (_i / 10) * 10));
            bytes1 b1 = bytes1(temp);
            bstr[k] = b1;
            _i /= 10;
        }
        return string(bstr);
    }
}
function uint2str(uint256 _i)
    internal
    pure
    returns (string memory _uintAsString)
{
    if (_i == 0) {
        return "0";
    }
    uint256 j = _i;
    uint256 len;
    while (j != 0) {
        len++;
        j /= 10;
    }
    bytes memory bstr = new bytes(len);
    uint256 k = len;
    while (_i != 0) {
        k = k - 1;
        uint8 temp = (48 + uint8(_i - (_i / 10) * 10));
        bytes1 b1 = bytes1(temp);
        bstr[k] = b1;
        _i /= 10;
    }
    return string(bstr);
}

/**
 * @dev Convert uint to string.
 * @param _i - uint256 to be converted to string.
 * @return _uintAsString
 */