V2 extends @Nullable Object>
      Table<R, C, V2> transformValues(
          Table<R, C, V1> fromTable, Function<? super V1, V2> function) {
    return new TransformedTable<>(fromTable, function);
  }

  private static class TransformedTable<
          R extends @Nullable Object,
          C extends @Nullable Object,
          V1 extends @Nullable Object,
          V2 extends @Nullable Object>