return new SetMultimapBuilder<K0, @Nullable Object>() {
        @Override
        public <K extends K0, V extends @Nullable Object> SetMultimap<K, V> build() {
          return Multimaps.newSetMultimap(
              MultimapBuilderWithKeys.this.<K, V>createMap(),
              new HashSetSupplier<V>(expectedValuesPerKey));
        }
      };
    }

      return new SetMultimapBuilder<K0, @Nullable Object>() {
        @Override
        public <K extends K0, V extends @Nullable Object> SetMultimap<K, V> build() {
          return Multimaps.newSetMultimap(
              MultimapBuilderWithKeys.this.<K, V>createMap(),
              new HashSetSupplier<V>(expectedValuesPerKey));
        }
      };
    }