def test_empty_subdir2(self):
        self.auth.creds_subdir = None
        try:
            self.auth.load_creds()
        except ValueError:
            pass
        except Exception as e:
            self.fail('Unexpected exception thrown: %s' % e)
        else:
            self.fail('ValueError exception not thrown.')
an 'astring' is an 'atom' or a 'string'
dataset/ETHPy150Open nltk/nltk/nltk/test/unit/test_twitter_auth.py/TestCredentials.test_empty_subdir2--crossover with--dataset/ETHPy150Open scanner/asimap/asimap/parse.py/IMAPClientCommand._p_astring