return new SortedSetMultimapBuilder<K0, V0>() {
        @Override
        public <K extends K0, V extends V0> SortedSetMultimap<K, V> build() {
          return Multimaps.newSortedSetMultimap(
              MultimapBuilderWithKeys.this.<K, V>createMap(), new TreeSetSupplier<V>(comparator));
        }
      };
    }

    /** Uses an {@link EnumSet} to store value collections. */

      return new SortedSetMultimapBuilder<K0, V0>() {
        @Override
        public <K extends K0, V extends V0> SortedSetMultimap<K, V> build() {
          return Multimaps.newSortedSetMultimap(
              MultimapBuilderWithKeys.this.<K, V>createMap(), new TreeSetSupplier<V>(comparator));
        }
      };
    }

    /** Uses an {@link EnumSet} to store value collections. */