### Question:
ProtoUtils { public static <T extends Message> Metadata.Key<T> keyForProto(T instance) { return Metadata.Key.of( instance.getDescriptorForType().getFullName() + Metadata.BINARY_HEADER_SUFFIX, metadataMarshaller(instance)); } private  ProtoUtils(); @ExperimentalApi("https://github.com/grpc/grpc-java/issues/1787") static void setExtensionRegistry(ExtensionRegistry registry); static Marshaller<T> marshaller(final T defaultInstance); static Metadata.Key<T> keyForProto(T instance); @ExperimentalApi("https://github.com/grpc/grpc-java/issues/4477") static Metadata.BinaryMarshaller<T> metadataMarshaller(T instance);  }### Answer:
@Test public void keyForProto() { assertEquals("google.protobuf.Type-bin", ProtoUtils.keyForProto(Type.getDefaultInstance()).originalName()); }