public async Task RefreshTodos()
{
var todos = await _service.ReadAll();
if (todos == null)
{
_notifier.ShowError("Server returned a null list of todos");
return;
}
var observableTodoItems = todos.Select(x => new ObservableTodoItem(x)).OrderByDescending(x => x.ModifiedAt);
TodoItems = new ObservableCollection <ObservableTodoItem>(observableTodoItems);
StatisticsLabel = string.Format("Tasks added since app start: {0}", _service.GetTasksCreatedCount());
}