for (int i = 0; i < startIndex; i++) {
        previousElements.push(nextElements.pop());
      }
    }

    @Override
    public void add(E e) {
      if (!features.contains(IteratorFeature.SUPPORTS_ADD)) {
        throw PermittedMetaException.UOE;
      }

      previousElements.push(e);
      stackWithLastReturnedElementAtTop = null;
    }

    @Override

      for (int i = 0; i < startIndex; i++) {
        previousElements.push(nextElements.pop());
      }
    }

    @Override
    public void add(E e) {
      if (!features.contains(IteratorFeature.SUPPORTS_ADD)) {
        throw PermittedMetaException.UOE;
      }

      previousElements.push(e);
      stackWithLastReturnedElementAtTop = null;
    }

    @Override