@Override
 protected void addOverlayKeys(List<OverlayKey> keys) {
   super.addOverlayKeys(keys);
   keys.add(
       new OverlayPreferenceStore.OverlayKey(
           OverlayPreferenceStore.BOOLEAN, RubyPreferenceConstants.EDITOR_FOLDING_INIT_REQUIRES));
 }
 @Override
 protected void addInitiallyFoldOptions(Group group) {
   super.addInitiallyFoldOptions(group);
   createCheckBox(
       group,
       RubyFoldingMessages.RubyFoldingPreferenceBlock_initRequires,
       RubyPreferenceConstants.EDITOR_FOLDING_INIT_REQUIRES);
 }