code: def run(self, request_cb, notification_cb):
          
          self._request_cb = request_cb
          self._notification_cb = notification_cb
          self._msgpack_stream.run(self._on_message)
          self._request_cb = None
          self._notification_cb = None
docs: Run the event loop to receive requests and notifications from Nvim.
  
          While the event loop is running, `request_cb` and `_notification_cb`
          will be called whenever requests or notifications are respectively
          available.