setCount(prevEntry.getElement(), 0);
        prevEntry = null;
      }
    };
  }

  @Override
  Iterator<Entry<E>> descendingEntryIterator() {
    return new Iterator<Entry<E>>() {
      @CheckForNull AvlNode<E> current = lastNode();
      @CheckForNull Entry<E> prevEntry = null;

      @Override
      public boolean hasNext() {

        setCount(prevEntry.getElement(), 0);
        prevEntry = null;
      }
    };
  }

  @Override
  Iterator<Entry<E>> descendingEntryIterator() {
    return new Iterator<Entry<E>>() {
      @CheckForNull AvlNode<E> current = lastNode();
      @CheckForNull Entry<E> prevEntry = null;

      @Override
      public boolean hasNext() {