code: function isSimpleRange(classRange) {
    const {from, to} = classRange;
    return (
      from.codePoint >= DIGIT_0_CP && from.codePoint <= DIGIT_9_CP &&
      to.codePoint >= DIGIT_0_CP && to.codePoint <= DIGIT_9_CP
    ) || (
      from.codePoint >= UPPER_A_CP && from.codePoint <= UPPER_Z_CP &&
      to.codePoint >= UPPER_A_CP && to.codePoint <= UPPER_Z_CP
    ) || (
      from.codePoint >= LOWER_A_CP && from.codePoint <= LOWER_Z_CP &&
      to.codePoint >= LOWER_A_CP && to.codePoint <= LOWER_Z_CP
    );
  }
docs: Checks if a range is included either in 0-9, a-z or A-Z
  @param classRange
  @returns {boolean}