docs: public void removeLoadedExtension(Extension extension) {
  		if (extension == null) {
  			throw new IllegalArgumentException("Parameter extension must not be null.");
  		}
  
  		if (loadedExtensions != null && loadedExtensions.contains(extension)) {
  			loadedExtensions.remove(extension);
  			extension.setAddOn(null);
  		}
  	}