This is a summary of the API changes to enable multipart.

New.java

public App extends Application {
  GsonBuilder builder = new GsonBuilder().registerTypeAdapter(Point.class, new RestAdapterTest.PointTypeAdapter());
  final Charset utf_16 = Charset.forName("UTF-16");
  
  Pipeline pipeline = new Pipeline(url);
  PipeConfig config = new PipeConfig(url, ListClassId.class);
  config.setEncoding(utf_16);
  config.setRequestBuilder(new GsonRequestBuilder(builder));
  
  RestAdapter<ListClassId> restPipe = (RestAdapter<ListClassId>) pipeline.pipe(ListClassId.class, config);
}

Old.java

public App extends Application {

  GsonBuilder builder = new GsonBuilder().registerTypeAdapter(Point.class, new RestAdapterTest.PointTypeAdapter());
  
  Pipeline pipeline = new Pipeline(url);
  PipeConfig config = new PipeConfig(url, ListClassId.class);
  config.setGsonBuilder(builder);
  
  RestAdapter<ListClassId> restPipe = (RestAdapter<ListClassId>) pipeline
          .pipe(ListClassId.class, config);

}