code: func (c *Client) PendingRequestsCount() int {
  	n := atomic.LoadUint32(&c.pendingRequestsCount)
  	return int(n) + len(c.requestsChan)
  }
docs: // PendingRequestsCount returns the instant number of pending requests.
  //
  // The main purpose of this function is to use in load-balancing schemes where
  // load should be balanced between multiple rpc clients.
  //
  // Don't forget starting the client with Client.Start() before calling
  // this function.