@Override
          public Iterator<Sdk> getAllListItems() {
            Application application = ApplicationManager.getApplication();
            if (application == null) {
              return Collections.singletonList((Sdk)null).iterator();
            }
            ArrayList<Sdk> allJdks = new ArrayList<>(Arrays.asList(ProjectJdkTable.getInstance().getAllJdks()));
            allJdks.add(0, null);
            return allJdks.iterator();
          }
@Override
          public Iterator<Sdk> getAllListItems()