def test_unstartedClose(self):
        """
        If L{ConnectionPool.close} is called without L{ConnectionPool.start}
        having been called, the pool's startup event is cancelled.
        """
        reactor = EventReactor(False)
        pool = ConnectionPool('twisted.test.test_adbapi', cp_reactor=reactor)
        # There should be a startup trigger waiting.
        self.assertEqual(reactor.triggers, [('after', 'startup', pool._start)])
        pool.close()
        # But not anymore.
        self.assertFalse(reactor.triggers)

        If L{ConnectionPool.close} is called without L{ConnectionPool.start}
        having been called, the pool's startup event is cancelled.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/test/test_adbapi.py