code: function normalize(value, options) {
    var settings = options || {}
    var allowApostrophes = settings.allowApostrophes
    var allowDashes = settings.allowDashes
    var result = (typeof value === 'string' ? value : toString(value))
      .toLowerCase()
      .replace(APOSTROPHE, QUOTE)
  
    if (allowApostrophes && allowDashes) {
      return result
    }
  
    if (allowApostrophes) {
      return result.replace(DASH, EMPTY)
    }
  
    if (allowDashes) {
      return result.replace(QUOTE, EMPTY)
    }
  
    return result.replace(ALL, EMPTY)
  }
docs: /* Normalize `value`.