final SerializerHackRemoteServiceAsync rpcProxy = (SerializerHackRemoteServiceAsync) com.google.gwt.core.client.GWT
.create(SerializerHackRemoteService.class);
final ServiceDefTarget serviceDefTarget = (ServiceDefTarget) rpcProxy;
serviceDefTarget.setServiceEntryPoint(URL);
final HasSerializer serializerHost = (HasSerializer) rpcProxy;
final Serializer serializer = serializerHost.getSerializer();
this.delayTestFinish(DELAY);
rpcProxy.echo(tree, new AsyncCallback() {
public void onSuccess(final Object result) {