code: def handle_write(self):
          
          with self.lock:
              logger.debug("handle_write: queue: {0!r}".format(self._write_queue))
              try:
                  job = self._write_queue.popleft()
              except IndexError:
                  return
              if isinstance(job, WriteData):
                  self._do_write(job.data) # pylint: disable=E1101
              elif isinstance(job, ContinueConnect):
                  self._continue_connect()
              elif isinstance(job, StartTLS):
                  self._initiate_starttls(**job.kwargs)
              elif isinstance(job, TLSHandshake):
                  self._continue_tls_handshake()
              else:
                  raise ValueError("Unrecognized job in the write queue: "
                                          "{0!r}".format(job))
docs: Handle the 'channel writable' state. E.g. send buffered data via a
          socket.