summarize-classes

public abstract class BindingActivity<B extends ViewDataBinding, VM extends ActivityViewModel> extends AppCompatActivity {
 
   private B binding;
   private VM viewModel;
 
   public B getBinding() {
       return binding;
   }
}
 
 
public abstract class ActivityViewModel<A extends AppCompatActivity>
       extends BaseObservable {
 
   protected A activity;
 
   public ActivityViewModel(A activity) {
       this.activity = activity;
   }
 
   public A getActivity() {
       return activity;
   }
}