code: function checkClassRange(from, to) {
    if (from.kind === 'control' || to.kind === 'control' || (!isNaN(from.codePoint) && !isNaN(to.codePoint) && from.codePoint > to.codePoint)) {
      throw new SyntaxError(`Range ${from.value}-${to.value} out of order in character class`);
    }
  }
docs: Checks class range