@Test
void onConnect() {

    // SETUP
    final MqttDevice device = new MqttDevice();
    final String topic1 = "topic1";
    final String topic2 = "topic2";
    device.setTopics(String.join(",", topic1, topic2));
    when(this.mqttClientAdapter.getDevice()).thenReturn(device);
    final Mqtt3ConnAck ack = mock(Mqtt3ConnAck.class);
    final Throwable throwable = null;
    // CALL
    this.instance.onConnect(this.mqttClientAdapter, ack, throwable);
    // VERIFY
    verify(this.mqttClientAdapter).subscribe(topic1, DEFAULT_QOS);
    verify(this.mqttClientAdapter).subscribe(topic2, DEFAULT_QOS);
}