viewport(options) {
    var _width, _height, _scale, _minimum, _maximum, _scalable; // var width, height, scale, minimum, maximum, scalable;


    var $viewport = this.document.querySelector("meta[name='viewport']");
    var parsed = {
      "width": undefined,
      "height": undefined,
      "scale": undefined,
      "minimum": undefined,
      "maximum": undefined,
      "scalable": undefined
    };
    var newContent = [];
    var settings = {};
    /*
    * check for the viewport size
    * <meta name="viewport" content="width=1024,height=697" />
    */

    if ($viewport && $viewport.hasAttribute("content")) {
      let content = $viewport.getAttribute("content");

      let _width = content.match(/width\s*=\s*([^,]*)/);

      let _height = content.match(/height\s*=\s*([^,]*)/);

      let _scale = content.match(/initial-scale\s*=\s*([^,]*)/);

      let _minimum = content.match(/minimum-scale\s*=\s*([^,]*)/);

      let _maximum = content.match(/maximum-scale\s*=\s*([^,]*)/);

      let _scalable = content.match(/user-scalable\s*=\s*([^,]*)/);

      if (_width && _width.length && typeof _width[1] !== "undefined") {
        parsed.width = _width[1];
      }

      if (_height && _height.length && typeof _height[1] !== "undefined") {
        parsed.height = _height[1];
      }

      if (_scale && _scale.length && typeof _scale[1] !== "undefined") {
        parsed.scale = _scale[1];
      }

      if (_minimum && _minimum.length && typeof _minimum[1] !== "undefined") {
        parsed.minimum = _minimum[1];
      }

      if (_maximum && _maximum.length && typeof _maximum[1] !== "undefined") {
        parsed.maximum = _maximum[1];
      }

      if (_scalable && _scalable.length && typeof _scalable[1] !== "undefined") {
        parsed.scalable = _scalable[1];
      }
    }

    settings = Object(_utils_core__WEBPACK_IMPORTED_MODULE_1__["defaults"])(options || {}, parsed);

    if (options) {
      if (settings.width) {
        newContent.push("width=" + settings.width);
      }

      if (settings.height) {
        newContent.push("height=" + settings.height);
      }

      if (settings.scale) {
        newContent.push("initial-scale=" + settings.scale);
      }

      if (settings.scalable === "no") {
        newContent.push("minimum-scale=" + settings.scale);
        newContent.push("maximum-scale=" + settings.scale);
        newContent.push("user-scalable=" + settings.scalable);
      } else {
        if (settings.scalable) {
          newContent.push("user-scalable=" + settings.scalable);
        }

        if (settings.minimum) {
          newContent.push("minimum-scale=" + settings.minimum);
        }

        if (settings.maximum) {
          newContent.push("minimum-scale=" + settings.maximum);
        }
      }

      if (!$viewport) {
        $viewport = this.document.createElement("meta");
        $viewport.setAttribute("name", "viewport");
        this.document.querySelector("head").appendChild($viewport);
      }

      $viewport.setAttribute("content", newContent.join(", "));
      this.window.scrollTo(0, 0);
    }

    return settings;
  }
Get or Set the viewport element
@param {object} [options]
@param {string} [options.width]
@param {string} [options.height]
@param {string} [options.scale]
@param {string} [options.minimum]
@param {string} [options.maximum]
@param {string} [options.scalable]