code: protected void unregisterElementErrListener(MediaElement element, final ListenerSubscription subscription) {
  		if (element == null || subscription == null) {
  			return;
  		}
  		element.removeErrorListener(subscription);
  	}
docs: Unregisters the error listener from the media element using the provided
  subscription.
  
  @param element      the {@link MediaElement}
  @param subscription the associated {@link ListenerSubscription}