error handling

TodoListViewModel3.kt

viewModelScope.launch {
    getAllTodosUseCase(force)
        .onStart { _refreshing.value = true }
        .onCompletion { _refreshing.value = false }
        .collect { response ->
            when (response) {
                is Result.Success -> _todos.value = response.result
                is Result.Failure -> _error.value = response.error
            }
        }
}