SearchViewModel.kt

class SearchViewModel(private val api: SearchAPI, private val dao: BookmarkDao) : DisposableViewModel() {
    private var query: String = ""
        get() = if (field.isEmpty()) "MVVM" else field

    private val _refreshing: NotNullMutableLiveData<Boolean> = NotNullMutableLiveData(false)
    val refreshing: LiveData<Boolean>
        get() = _refreshing

    private val _items: NotNullMutableLiveData<List<Repository>> = NotNullMutableLiveData(arrayListOf())
    val items: LiveData<List<Repository>>
        get() = _items