'Handle server responses for the SHORT state in which the server is
expected to send a single line response.
Parse the response and fire the deferred which is waiting on receipt of
a complete response.  Transition the state back to WAITING.
@type line: L{bytes}
@param line: A line received from the server.
@rtype: L{bytes}
@return: The next state.'

def state_SHORT(self, line):

    (deferred, self._waiting) = (self._waiting, None)
    self._unblock()
    (code, status) = _codeStatusSplit(line)
    if (code == OK):
        deferred.callback(status)
    else:
        deferred.errback(ServerErrorResponse(status))
    return 'WAITING'
