def __repr__(self):
        return "<Requirement(package={package}, version='{version}')>".format(
            package=self.package, version=self.version)
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)