code: @ExperimentalApi("https://github.com/grpc/grpc-java/issues/4477")
    public static <T extends Message> Metadata.BinaryMarshaller<T> metadataMarshaller(T instance) {
      return ProtoLiteUtils.metadataMarshaller(instance);
    }
docs: Produce a metadata marshaller for a protobuf type.
  
  @since 1.13.0