code: protected void shutdownClient() {
  		if (serviceClient != null) {
  			try {
  				serviceClient.close();
  				serviceClient = null;
  			} catch (Exception ex) {
  				logger.warn("Couldn't close Azure IoT service client: {}", ex.getMessage());
  			}
  		}
  	}
docs: Stops the client and releases resources.
  <b>There's no need to call this explicitly!</b>