Now, uber-properties are amazing and we are going to possibly want to use them a great deal, so it is sensible to simply produce a base course that does this for all subclasses. I think you understand what The bottom course will probably be called. So your DataContext for "video_length_textbox" https://share.evernote.com/note/f404b8b9-8407-e9b8-74a2-7bb0637d59f3