https://github.com/googlesamples/android-architecture/blob/dev-todo-mvvm-live/todoapp/app/src/main/java/com/example/android/architecture/blueprints/todoapp/tasks/TasksViewModel.java

TasksViewModel.java

public class TasksViewModel extends AndroidViewModel {

    // These observable fields will update Views automatically
    public final ObservableList<Task> items = new ObservableArrayList<>();
    public final ObservableBoolean dataLoading = new ObservableBoolean(false);
    public final ObservableField<String> currentFilteringLabel = new ObservableField<>();
    public final ObservableField<String> noTasksLabel = new ObservableField<>();
    public final ObservableField<Drawable> noTaskIconRes = new ObservableField<>();
    public final ObservableBoolean empty = new ObservableBoolean(false);
    public final ObservableBoolean tasksAddViewVisible = new ObservableBoolean();
 
  ...  
}