code: def start(self, timeout=None):
          
          if self._handler_thread and self._handler_thread.isAlive():
              raise RuntimeError('Message handler thread already started')
          self._server.start(timeout)
          self.ioloop = self._server.ioloop
          if self._handler_thread:
              self._handler_thread.set_ioloop(self.ioloop)
              self._handler_thread.start(timeout)
docs: Start the server in a new thread.
  
          Parameters
          ----------
          timeout : float or None, optional
              Time in seconds to wait for server thread to start.