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 _init_gui(self):
    self._size_spin_button = gtk.SpinButton(
      gtk.Adjustment(
        value=0,
        lower=self._min_size,
        upper=self._max_size,
        step_incr=1,
        page_incr=10,
      ),
      digits=0)