isIE() {
    if (typeof window === 'undefined') {
      return false;
    }

    const userAgent = window.navigator.userAgent;

    const msie = userAgent.indexOf('MSIE ');
    if (msie > 0) {
      // IE 10 or older => return version number
      return parseInt(userAgent.substring(msie + 5, userAgent.indexOf('.', msie)), 10);
    }

    const trident = userAgent.indexOf('Trident/');
    if (trident > 0) {
      // IE 11 => return version number
      const rv = userAgent.indexOf('rv:');
      return parseInt(userAgent.substring(rv + 3, userAgent.indexOf('.', rv)), 10);
    }

    const edge = userAgent.indexOf('Edge/');
    if (edge > 0) {
      // IE 12 (aka Edge) => return version number
      return parseInt(userAgent.substring(edge + 5, userAgent.indexOf('.', edge)), 10);
    }

    // other browser
    return false;
  }
Retuns if the browser is Internet Explorer.
@returns {boolean} - TRUE if the browser is IE.