@Override
 public void unregisterOperators() {
   Set<String> keys = OperatorService.getOperatorKeys();
   for (OperatorDescription description : getOperatorDescriptions()) {
     if (keys.contains(description.getKey())) OperatorService.unregisterOperator(description);
   }
 }
 @Override
 public void registerOperators() throws OperatorCreationException {
   Set<String> keys = OperatorService.getOperatorKeys();
   for (OperatorDescription description : getOperatorDescriptions()) {
     if (!keys.contains(description.getKey()))
       OperatorService.registerOperator(description, docBundle);
   }
 }
 @Override
 public void performAction(OperatorDescription description) {
   try {
     Operator operator = OperatorService.createOperator(description);
     RapidMinerGUI.getMainFrame().getActions().insert(Collections.singletonList(operator));
   } catch (Exception e) {
     SwingTools.showSimpleErrorMessage("cannot_instantiate", e, description.getName());
   }
 }