@Override
    public Builder<E> addAll(Iterator<? extends E> elements) {
      while (elements.hasNext()) {
        add(elements.next());
      }
      return this;
    }

    private void dedupAndCoalesceAndDeleteEmpty() {
      dedupAndCoalesce(false);

      // If there was a setCount(elem, 0), those elements are still present.  Eliminate them.
      int size = 0;
      for (int i = 0; i < length; i++) {