<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def _write(self, request):
 """Actually serialize and write the request."""

    with sw("serialize_request"):
      request_str = request.SerializeToString()
    with sw("write_request"):
      with catch_websocket_connection_errors():
        self._sock.send(request_str)