or
RadRichTextBox radRichTextBox = ((RadRichTextBoxAutoComplete)currentPane).radRichTextBox;//Set Custom AnnotationItemGroupRangeEnd rangeEnd = new ItemGroupRangeEnd();ItemGroupRangeStart rangeStart = (ItemGroupRangeStart)rangeEnd.CreatePairedStart();rangeStart.Name = "GroupItem " + count++;//Place annotation around newly inserted textradRichTextBox.Document.InsertCustomAnnotationRange(radRichTextBox.Document.CaretPosition, radRichTextBox.Document.CaretPosition, rangeStart, rangeEnd);//Referesh editorradRichTextBox.UpdateEditorLayout();public override bool SkipPositionBefore{ get { return false; }}<telerik:RadTreeView telerik:StyleManager.Theme="Metro" SelectedItem="{Binding SelectedNomenclatuurnummer, Mode=OneWayToSource}" Margin="10,5" IsTriStateMode="True" IsOptionElementsEnabled="True" SelectionMode="Multiple" ItemsOptionListType="CheckList" ItemsSource="{Binding Nomenclatuurnummers}" HorizontalAlignment="Stretch" Grid.RowSpan="4" Grid.Column="1"> </telerik:RadTreeView>