def _codeStatusSplit(line):
    """
    Parse the first line of a multi-line server response.

    @type line: L{bytes}
    @param line: The first line of a multi-line server response.

    @rtype: 2-tuple of (0) L{bytes}, (1) L{bytes}
    @return: The status indicator and the rest of the server response.
    """
    parts = line.split(b' ', 1)
    if len(parts) == 1:
        return parts[0], b''
    return parts

    Parse the first line of a multi-line server response.

    @type line: L{bytes}
    @param line: The first line of a multi-line server response.

    @rtype: 2-tuple of (0) L{bytes}, (1) L{bytes}
    @return: The status indicator and the rest of the server response.
    
stackoverflow/venv/lib/python3.6/site-packages/twisted/mail/pop3client.py