This page (http://docs.telerik.com/devtools/wpf/api/html/t_telerik_windows_controls_data_propertygrid_editing_propertygridpreparededitoreventhandler.htm) lists PropertyGridPreparedEditorEventArgs as the type that the RadPropertyGrid PreparedEditor event should receive. That type doesn't exist (version 2016.1.112.45). If I try to just declare EventArgs, it blows up at run time.
How do I use this event?