def test_quoteStringArgument(self):
        """
        L{endpoints.quoteStringArgument} should quote backslashes and colons
        for interpolation into L{endpoints.serverFromString} and
        L{endpoints.clientFactory} arguments.
        """
        self.assertEqual(endpoints.quoteStringArgument("some : stuff \x5c"),
                         "some \x5c: stuff \x5c\x5c")

        L{endpoints.quoteStringArgument} should quote backslashes and colons
        for interpolation into L{endpoints.serverFromString} and
        L{endpoints.clientFactory} arguments.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/internet/test/test_endpoints.py