private static final ImmutableSet<String> VALID_NAME =
      ImmutableSet.of(
          // keep-sorted start
          "123.cn",
          "8server.shop",
          "a" + DELTA + "b.com",
          "abc.a23",
          "biz.com.ua",
          "f--1.com",
          "f--o",
          "f-_-o.cOM",
          "f11-1.com",
          "fOo",
          "f_a",

  private static final ImmutableSet<String> VALID_NAME =
      ImmutableSet.of(
          // keep-sorted start
          "123.cn",
          "8server.shop",
          "a" + DELTA + "b.com",
          "abc.a23",
          "biz.com.ua",
          "f--1.com",
          "f--o",
          "f-_-o.cOM",
          "f11-1.com",
          "fOo",
          "f_a",

        @Override
        @Nullable String chop(String str) {
          String result = i.chop(str);
          return result != null ? result : you.chop(str);
        }
      };
    }

    abstract @Nullable String chop(String str);

    static Chopper suffix(String suffix) {
      return new Chopper() {
        @Override
        @Nullable String chop(String str) {
          if (str.endsWith(suffix)) {

        @Override
        @Nullable String chop(String str) {
          String result = i.chop(str);
          return result != null ? result : you.chop(str);
        }
      };
    }

    abstract @Nullable String chop(String str);

    static Chopper suffix(String suffix) {
      return new Chopper() {
        @Override
        @Nullable String chop(String str) {
          if (str.endsWith(suffix)) {

 *   Added utility `tf.keras.utils.FeatureSpace`, a one-stop shop for structured data preprocessing and encoding.