private void doFix(Editor editor, final DomFileElement<IdeaPlugin> element) {
    PsiClass extensionClass = myExtensionClassPointer.getElement();
    if (extensionClass == null || !extensionClass.isValid()) return;

    if (myEPCandidates.size() == 1) {
      registerExtension(element, myEPCandidates.iterator().next(), extensionClass);
    }
    else {
      final BaseListPopupStep<ExtensionPointCandidate> popupStep =
        new BaseListPopupStep<>(DevKitBundle.message("register.extension.fix.popup.title"), new ArrayList<>(myEPCandidates)) {
          @Override
          public PopupStep<?> onChosen(ExtensionPointCandidate selectedValue, boolean finalChoice) {
            registerExtension(element, selectedValue, extensionClass);
            return FINAL_CHOICE;
          }
        };
      JBPopupFactory.getInstance().createListPopup(popupStep).showInBestPositionFor(editor);
    }
  }
private void doFix(Editor editor, final DomFileElement<IdeaPlugin> element)