docs: private static String getCharacter(Table table, int code) {
      switch (table) {
        case UPPER:
          return UPPER_TABLE[code];
        case LOWER:
          return LOWER_TABLE[code];
        case MIXED:
          return MIXED_TABLE[code];
        case PUNCT:
          return PUNCT_TABLE[code];
        case DIGIT:
          return DIGIT_TABLE[code];
        default:
          // Should not reach here.
          throw new IllegalStateException("Bad table");
      }
    }