constructor(ctx) {
    /**
     * The context of the instance. Either a DOM element, an array of DOM
     * elements, a NodeList or a selector
     * @type {HTMLElement|HTMLElement[]|NodeList|string}
     * @access protected
     */
    this.ctx = ctx;
    /**
     * Specifies if the current browser is a IE (necessary for the node
     * normalization bug workaround). See {@link Mark#unwrapMatches}
     * @type {boolean}
     * @access protected
     */
    this.ie = false;
    const ua = window.navigator.userAgent;
    if (ua.indexOf('MSIE') > -1 || ua.indexOf('Trident') > -1) {
      this.ie = true;
    }
  }
@param {HTMLElement|HTMLElement[]|NodeList|string} ctx - The context DOM
element, an array of DOM elements, a NodeList or a selector