How make a API unit test with MVVM architecture in Android

Question

I have a project that uses Retrofit with MVVM architecture, but unfortunately I don't have much experience with unit testing, so I can't do a test on MVVM, I'm using Koin for dependency injection, I also had to mask some things in the code, unfortunately. Follow my code:

SomethingRepository

interface SomethingRepository {

    @GET("something/")
    suspend fun getSomethingList(@Query("page") page: Int): List<Something>

}

SomethingRepositoryData

class SomethingRepositoryData( private val repository: SomethingRepository ) {

suspend fun somethingList(page: Int = 1): List<Something> {
    return repository.getSomethingList(page)
}

}

SomethingViewModel

class SomethingViewModel(
    private val SomethingRepositoryData: SomethingRepositoryData
) : ViewModel() {

    private val _somethingList = MutableLiveData<List<Something>>()
    val somethingList: LiveData<List<Something>>
        get() = _somethingList


    fun getSomethingList() {
            CoroutineScope(Dispatchers.IO).launch {
                try {
                    somethingRepositoryData.somethingList().run {
                        _somethingList.postValue(this)
                    }
                } catch (e: Exception) {
                    // Do something
                }
            }
        }
}

SomethingTest ???

I dont have ideal, i see in the internet is necessary uses Mockito and create a new RepositoryData just for Mock, I dont understand very well how make a API unit test