def _send_request(self):
        """
        Sends the request to the backend.
        """
        if isinstance(self._worker, str):
            classname = self._worker
        else:
            classname = '%s.%s' % (self._worker.__module__,
                                   self._worker.__name__)
        self.request_id = str(uuid.uuid4())
        self.send({'request_id': self.request_id, 'worker': classname,
                   'data': self._args})