* ImmutableSortedMultiset#orderedBy(Comparator)}.
     */
    @SuppressWarnings("unchecked")
    public Builder(Comparator<? super E> comparator) {
      super(true); // doesn't allocate hash table in supertype
      this.comparator = checkNotNull(comparator);
      this.elements = (E[]) new Object[ImmutableCollection.Builder.DEFAULT_INITIAL_CAPACITY];