def _stringRepresentation(self, stringFunction):
        """
        The string representation of C{SSHTransportAddress} should be
        "SSHTransportAddress(<stringFunction on address>)".
        """
        addr = self.buildAddress()
        stringValue = stringFunction(addr)
        addressValue = stringFunction(addr.address)
        self.assertEqual(stringValue,
                         "SSHTransportAddress(%s)" % addressValue)

        The string representation of C{SSHTransportAddress} should be
        "SSHTransportAddress(<stringFunction on address>)".
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/conch/test/test_address.py