'Wait for response(s) to be put into the eventlet queue.  Since
each queue entry actually contains a list of JSON-ified responses,
combine them all into a single list to return.
Destroy the eventlet queue when done.'

def _wait_for_json_responses(self, num_responses=1):

    if (not self.resp_queue):
        return
    responses = []
    wait_time = CONF.cells.call_timeout
    try:
        for x in range(num_responses):
            json_responses = self.resp_queue.get(timeout=wait_time)
            responses.extend(json_responses)
    except queue.Empty:
        raise exception.CellTimeout()
    finally:
        self._cleanup_response_queue()
    return responses
