def _nameResolution(self, host):
        """
        Resolve the hostname string into a tuple containing the host
        IPv6 address.
        """
        return self._deferToThread(
            self._getaddrinfo, host, 0, socket.AF_INET6)

        Resolve the hostname string into a tuple containing the host
        IPv6 address.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/internet/endpoints.py