ContentAttributeDialog.Result Command_Content_WithAttribute_Dialog() => ContentAttributeDialog.Run(WindowParent, GetSelectionNodes());
 ContentAttributeDialog.Result Command_Content_Descendants_WithAttribute_Dialog() => ContentAttributeDialog.Run(WindowParent, GetSelectionNodes().SelectMany(node => node.Descendants()).Distinct().ToList());
 ContentAttributeDialog.Result Command_Content_Ancestor_Dialog() => ContentAttributeDialog.Run(WindowParent, GetSelectionNodes().SelectMany(node => node.Parents()).Distinct().ToList());