It is not referencing them when adding, and also it is connecting
to the "destroy" signal, emitted on dispose, so there is no risk
of storing finalized objects.
https://bugzilla.gnome.org/show_bug.cgi?id=634781
* Make sure all source files have a LGPL copyright header, and standardize
non-standard variations of the header to a common form.
* Check and update all copyright notices.
* Remove 'Written By:' lines. They are universally incomplete and
typically indicate only who started a particular file.
https://bugzilla.gnome.org/show_bug.cgi?id=634550