Legacy Theme in MPR

@MprTheme("reindeer")
public class Configuration implements AppShellConfigurator {
}

public class MainLayout extends Div implements RouterLayout {
}

@Route(value = "", layout = MainLayout.class)
public class RootTarget extends Div {
    public RootTarget() {
      LegacyWrapper addressbookWrapper = new LegacyWrapper(
                  new AddressbookLayout());
      add(addressbookWrapper);
    }
}