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 remove_item(self, item):
    if (self._locker.is_unlocked("prevent_removal_below_min_size")
        and len(self._items) == self._min_size):
      return