def test_dirs(self):
        """
        CompleteDirs produces zsh shell-code that completes directory names.
        """
        c = usage.CompleteDirs()
        got = c._shellCode('some-option', usage._ZSH)
        self.assertEqual(got, ':some-option:_directories')

        c = usage.CompleteDirs(descr="some action", repeat=True)
        got = c._shellCode('some-option', usage._ZSH)
        self.assertEqual(got, '*:some action:_directories')

        CompleteDirs produces zsh shell-code that completes directory names.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/test/test_usage.py