code: func (w *Worker) EnqueueRPC(
  	routeStr string,
  	metadata map[string]interface{},
  	reply, arg proto.Message,
  ) (jid string, err error) {
  	opts := w.enqueueOptions(w.opts)
  	return workers.EnqueueWithOptions(rpcQueue, class, &rpcInfo{
  		Route:    routeStr,
  		Metadata: metadata,
  		Arg:      arg,
  		Reply:    reply,
  	}, opts)
  }
docs: // EnqueueRPC enqueues rpc job to worker