def createClientEndpoint(self, reactor, clientFactory, **connectArgs):
        """
        Creates a L{HostnameEndpoint} instance where the hostname is resolved
        into a single IPv6 address.
        """
        address = HostnameAddress(b"ipv6.example.com", 80)
        endpoint = endpoints.HostnameEndpoint(
            deterministicResolvingReactor(reactor, ['1:2::3:4']),
            b"ipv6.example.com", address.port, **connectArgs
        )
        return (endpoint, ('1:2::3:4', address.port, clientFactory,
                connectArgs.get('timeout', 30),
                connectArgs.get('bindAddress', None)),
                address)

        Creates a L{HostnameEndpoint} instance where the hostname is resolved
        into a single IPv6 address.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/internet/test/test_endpoints.py