def __init__(self, groups=None):
        super(GroupedRequirements, self).__init__(NamedRequirements)
        self.groups = groups or self.default_groups
        self.filename = None
        self.create_default_groups()
def _on_event_box_enter_notify_event(self, event_box, event):
    if event.detail != gtk.gdk.NOTIFY_INFERIOR:
      self._hbox_buttons.show()