}

  @SuppressWarnings({"rawtypes", "unchecked"})
  private static <K extends @Nullable Object>
      SortedSetMultimapBuilder<K, Comparable<?>> rawtypeToWildcard(
          SortedSetMultimapBuilder<K, Comparable> setMultimapBuilder) {
    return (SortedSetMultimapBuilder) setMultimapBuilder;
  }

  @GwtIncompatible
  @J2ktIncompatible
    public void testSerialization() throws Exception {