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 reorder_item(self, item, new_position):
    orig_position = self._get_item_position(item)
    processed_new_position = super().reorder_item(item, new_position)