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

TasksViewModel.kt

interface TasksActions {
    fun onTaskDetails(taskId: String)
    fun onNewTask()
}

class TasksViewModel(private val tasksRepository: TasksRepository,
                     // The injected callbacks for highlevel actions like onNewTask, onTaskDetails
                     private val tasksActions: TasksActions) : BaseReactViewModel<TasksViewData>(),
                                                               // The taks item Actions
                                                               TasksViewItemActions,
                                                               // The tasks view actions like the create new task FAB 
                                                               TasksViewActions {
...