How do you configure the MQTT client id in a MqttConnector?

I’m evaluating io.confluent.connect.mqtt.MqttSourceConnector and io.confluent.connect.mqtt.MqttSinkConnector .

I notice that the connector misses MQTT messages from Mosqiutto when connect is not running. Even tough mqtt.clean.session.enabled is set to false .
In the Mosquitto logs I see that the connector uses a different MQTT client id after each restart. If I could fix the client id, the MQTT borker would deliver message received when the connector reconnects. However, in the documentation I can’t find any property to set the MQTT client id.

I’m wondering, is this bit of configuration undocumented or just missing altogether?