def test_get_async_param_deprecation(self):
        """
        L{twisted.python.compat._get_async_param} raises a deprecation
        warning if async keyword argument is passed.
        """
        self.assertEqual(
            _get_async_param(isAsync=None, **{'async': False}), False)
        currentWarnings = self.flushWarnings(
            offendingFunctions=[self.test_get_async_param_deprecation])
        self.assertEqual(
            currentWarnings[0]['message'],
            "'async' keyword argument is deprecated, please use isAsync")

        L{twisted.python.compat._get_async_param} raises a deprecation
        warning if async keyword argument is passed.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/test/test_compat.py