### Question:
ProtoUtils { public static <T extends Message> Marshaller<T> marshaller(final T defaultInstance) { return ProtoLiteUtils.marshaller(defaultInstance); } 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 testRoundtrip() throws Exception { Marshaller<Type> marshaller = ProtoUtils.marshaller(Type.getDefaultInstance()); InputStream is = marshaller.stream(proto); is = new ByteArrayInputStream(ByteStreams.toByteArray(is)); assertEquals(proto, marshaller.parse(is)); }