code: public GrpcServiceBuilder addServices(BindableService... bindableServices) {
          requireNonNull(bindableServices, "bindableServices");
          return addServices(ImmutableList.copyOf(bindableServices));
      }
docs: Adds gRPC {@link BindableService}s to this {@link GrpcServiceBuilder}. Most gRPC service
  implementations are {@link BindableService}s.