public void Filter(string query)
{
var count = Items.Count;
var items = !string.IsNullOrWhiteSpace(query) ? OriginalValues.Where(i => i.Name.Contains(query)).ToList() : OriginalValues;
Items = items;
EmptyText.Visibility = Items.Count > 0 ? ViewStates.Gone : ViewStates.Visible;
NotifyItemRangeRemoved(0, count);
NotifyItemRangeInserted(0, Items.Count);
}
public IEnumerator <KeyValuePair <TKey, TValue> > GetEnumerator() => OriginalValues.Where(item => IsKeyFiltered(item.Key)).GetEnumerator();
