code: func (r *Room) Entry(ctx context.Context, msg []byte) (*JoinResponse, error) {
  	s := pitaya.GetSessionFromCtx(ctx)
  	err := s.Bind(ctx, strconv.Itoa(int(s.ID())))
  	if err != nil {
  		return nil, pitaya.Error(err, "RH-000", map[string]string{"failed": "bind"})
  	}
  	return &JoinResponse{Result: "ok"}, nil
  }
docs: // Entry is the entrypoint