code: func (ns *NatsRPCClient) SendPush(userID string, frontendSv *Server, push *protos.Push) error {
  	topic := GetUserMessagesTopic(userID, frontendSv.Type)
  	msg, err := proto.Marshal(push)
  	if err != nil {
  		return err
  	}
  	return ns.Send(topic, msg)
  }
docs: // SendPush sends a message to a user