class ExampleUserUseCase(private val repository: ExampleUserRepository) {
    sealed class Result {
      object InProgess
      data class OnSuccess(val users: List<ExampleUser>) : Result()
      data class OnError(val error: Throwable) : Result()
    }

  fun execute() {
        repository.getExampleUserList()
                .map(mapper::map)
                .subscribeOn(Schedulers.io())
                .observeOn(AndroidSchedulers.mainThread())
                .subscribe(Result.OnSucess, Result.OnError)
                .startWith(Result.InProgress)
    }

    private fun success(memes: List<ExampleUser>) {
        liveData.value = Result.OnSuccess(users)
    }

    private fun error(throwable: Throwable) {
        liveData.value = Result.OnError(throwable)
    }
}