*
     * @throws IllegalArgumentException if any two keys are equal according to the comparator (which
     *     might be the keys' natural order)
     */
    @Override
    public ImmutableSortedMap<K, V> build() {
      return buildOrThrow();
    }

    /**
     * Returns a newly-created immutable sorted map, or throws an exception if any two keys are
     * equal.
     *

     *
     * @throws IllegalArgumentException if any two keys are equal according to the comparator (which
     *     might be the keys' natural order)
     */
    @Override
    public ImmutableSortedMap<K, V> build() {
      return buildOrThrow();
    }

    /**
     * Returns a newly-created immutable sorted map, or throws an exception if any two keys are
     * equal.
     *