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 __enter__(self):
        entering = not transaction_states[self.using]
        transaction_states[self.using].begin()
        self._no_monkey.__enter__(self)
        if entering:
            on_commit(transaction_states[self.using].commit, self.using)