@RunWith(JUnit4::class)
class MainViewModelTest {
    @Rule
    @JvmField
    val instantTaskExecutorRule = InstantTaskExecutorRule()
    @Mock lateinit var repo: GithubRepository
    @Mock  lateinit var githubApi: GithubApi
    @Mock  lateinit var application: TrendingApp
    lateinit var viewModel: MainViewModel
    @Mock  lateinit var dataObserver: Observer<Event<DataState<List<TrendingResponse>>>>
    @Mock  lateinit var loadingObserver: Observer<Boolean>
    private val threadContext = newSingleThreadContext("UI thread")
    private val trendingList : List<TrendingResponse> = listOf()
    @Before
    fun setUp() {
        MockitoAnnotations.initMocks(this)
        Dispatchers.setMain(threadContext)
        viewModel = MainViewModel(application, repo)
    }
`   `
    @test
    fun test_TrendingRepo_whenSuccess() {
        //Assemble
        Mockito.when`(githubApi.getTrendingListAsync(“java”, “daily”))`
            .thenAnswer{ return@thenAnswer trendingList.toDeferred() }
        //Act
        viewModel.trendingLiveData.observeForever(dataObserver)
        viewModel.loadingState.observeForever(loadingObserver)
        viewModel.getTrendingData("java", "daily")
        //Verify
        verify(loadingObserver).onChanged(true)
        verify(dataObserver).onChanged(Event(DataState.Success(trendingList)))
        verify(loadingObserver).onChanged(false)
    }
    @After
    fun tearDown() {
        Dispatchers.resetMain()
        threadContext.close()
    }
}