def __missing__(self, key):
        if self.default_factory is None:
            raise KeyError(key)
        else:
            ret = self[key] = self.default_factory(name=key)
            return ret
def execute(self, sql, params=None):
        result = self._no_monkey.execute(self, sql, params)
        if transaction_states[self.db.alias] and is_sql_dirty(sql):
            transaction_states[self.db.alias].mark_dirty()
        return result