def close_conn(self):
        conn = self.conn
        conn.quit()
Undo aggregate operation when pool error raised.
dataset/ETHPy150Open airbnb/airflow/airflow/contrib/hooks/ftp_hook.py/FTPHook.close_conn--crossover with--dataset/ETHPy150Open BU-NU-CLOUD-SP16/Trusted-Platform-Module-nova/nova/virt/xenapi/driver.py/XenAPIDriver.undo_aggregate_operation