@Override
 public boolean isEnabled(final AbstractNode obj) {
   if (obj instanceof AbstractPackageNode) {
     return ((AbstractPackageNode) obj).getView().isEnabled();
   }
   return obj.isEnabled();
 }
 @Override
 public boolean isEnabled(AbstractNode obj) {
   if (obj instanceof FilePackage) {
     return ((FilePackage) obj).getView().isEnabled();
   }
   if (obj instanceof CrawledPackage) {
     return ((CrawledPackage) obj).getView().isEnabled();
   }
   return obj.isEnabled();
 }
 @Override
 public boolean isEnabled(AbstractNode obj) {
     return obj.isEnabled();
 }