code: public GrpcServiceBuilder supportedSerializationFormats(Iterable<SerializationFormat> formats) {
          requireNonNull(formats, "formats");
          for (SerializationFormat format : formats) {
              if (!GrpcSerializationFormats.isGrpc(format)) {
                  throw new IllegalArgumentException("Not a gRPC serialization format: " + format);
              }
          }
          supportedSerializationFormats = ImmutableSet.copyOf(formats);
          return this;
      }
docs: Sets the {@link SerializationFormat}s supported by this server. If not set, defaults to supporting binary
  protobuf formats. JSON formats are currently very inefficient and not recommended for use in production.
  
  <p>TODO(anuraaga): Use faster JSON marshalling.