@property
    def engine(self):
        global ENGINES
        if ENGINES not in self.db_url:
            engine = sqlalchemy.create_engine(self.db_url, echo=self.echo_sql)
            ENGINES[self.db_url] = engine
        return ENGINES[self.db_url]
dataset/ETHPy150Open openstack/stacktach-winchester/winchester/db/interface.py/DBInterface.engine/swapped operands of `not in`