filesystem.deleteRecursively(cacheDir)
    assertThat(cache["a"]).isNull()
  }

  /**
   * We had a long-lived bug where [DiskLruCache.trimToSize] could infinite loop if entries
   * being edited required deletion for the operation to complete.
   */
  @ParameterizedTest
  @ArgumentsSource(FileSystemParamProvider::class)

client = mqtt.Client(client_id="myclientid",clean_session=False)

client.on_connect = on_connect
client.on_message = on_message

client.connect("localhost",1883,60)
client.loop_forever()
```

Execute this example python program to watch for MQTT events on the console.

```py
python mqtt.py
```

Open another terminal and upload a JPEG image into `images` bucket.

```