@Override
 public void clear() {
   for (Index i : index) {
     storage.removeItem(getId(i.getId()));
   }
   index.clear();
   updateIndex();
 }
 @Override
 public void delete(long key) {
   for (Index i : index) {
     if (i.getId() == key) {
       index.remove(i);
       storage.removeItem(getId(key));
       updateIndex();
       break;
     }
   }
 }