* Builder} and its comparator.
     */
    @Override
    public ImmutableSortedSet<E> build() {
      @SuppressWarnings("unchecked") // we're careful to put only E's in here
      E[] contentsArray = (E[]) contents;
      ImmutableSortedSet<E> result = construct(comparator, size, contentsArray);
      this.size = result.size(); // we eliminated duplicates in-place in contentsArray

      if (n == elements.length) {
        sortAndDedup();
        /*
         * Sorting operations can only be allowed to occur once every O(n) operations to keep
         * amortized O(n log n) performance.  Therefore, ensure there are at least O(n) *unused*
         * spaces in the builder array.
         */
        int newLength = ImmutableCollection.Builder.expandedCapacity(n, n + 1);
        if (newLength > elements.length) {