Code review comment for lp:~julien-spautz/cable/clean-up

I have always had @junrreins problem; I fixed this in trunk but I presums that Julien Spautz's branch is based of an older revsion. To fix the compile error, you need to put '(Gtk.Container)' before topic so it looks like this:

Gtk.Container content = (Gtk.Container)topic.get_content_area ();

However, there are also some disagreementtwith the design. Until we can resolve them,' the branch should not be merged.