How to use the azure-iot-hub.azure.iot.hub.protocol.iot_hub_gateway_service_ap_is20190701_preview.IotHubGatewayServiceAPIs20190701Preview function in azure-iot-hub

def __init__(self, connection_string):
        """Initializer for a Digital Twin Service client.

        After a successful creation the class has been authenticated with IoTHub and
        it is ready to call the member APIs to communicate with IoTHub.

        :param: str connection_string: The authentication information
        (IoTHub connection string) to connect to IoTHub.

        :returns: DigitalTwinServiceClient object.
        """
        self.auth = ConnectionStringAuthentication(connection_string)
        self.protocol = protocol_client(self.auth, "https://" + self.auth["HostName"])