from umqtt.simple import MQTTClient client_id = "my_mqtt_client_id" broker_address = "mqtt://mqtt.eclipseprojects.io" client = MQTTClient(client_id, broker_address) client.set_last_will("mytopic/lastwilltopic", "I am disconnected.") client.connect() client.publish("mytopic/sensor", "Hello, MQTT!") client.disconnect()This code creates an MQTT client and sets the Last Will and Testament message as "I am disconnected." The client then connects to the broker, publishes a message to the topic "mytopic/sensor", disconnects, and sends the Last Will message to "mytopic/lastwilltopic" because the disconnection was not clean. In this example, umqtt.simple is the package library used to implement the MQTT client.