LinearGraphAnswer (@NotNull LinearGraphAction action) { LinearGraphAnswer answer = performAction(action); if (answer != null) { return answer; } VisibleGraphImpl.LinearGraphActionImpl delegateAction = new VisibleGraphImpl.LinearGraphActionImpl(convertToDelegate(action.getAffectedElement()), action.getType()); return delegateGraphChanged(myDelegateController.performLinearGraphAction(delegateAction)); }