code: function (featureStringCommaSeparated) {
    var arrayFeatures = featureStringCommaSeparated
      .split(',')
      .filter(function (x) { return x.length })
      .map(function (x) { return x.replace(/[\*\/]/g, '') }); // Eliminate XSS vuln
    var arrayUnsupportedFeatures = [];
    for (var i = 0; i < arrayFeatures.length; i++) {
      var supportedFeature = true;
      var fullFeature = arrayFeatures[i];
      if (contains(fullFeature, "~")) {
        if (contains(fullFeature, "Intl.~locale")) {
          supportedFeature = checkIntlLocale(window, fullFeature);
        } else {
          console.warn('Feature ' + fullFeature + ' can not be detected because it has not JavaScript API.');
        }
      } else {
        // Get the feature and the container Object
        var featureString = fullFeature.substring(fullFeature.lastIndexOf('.') + 1);
        if (contains(featureString, "@@")) {
          console.warn('Feature ' + featureString + ' can not be detected because it depends on Symbol.');
        } else {
          var objectString = fullFeature.substring(0, fullFeature.lastIndexOf('.'));
          var object = getDescendantProp(window, objectString);
          if (object !== undefined) {
            //if ((object.hasOwnProperty(featureString)) === false) {
            if ((featureString in object) === false) {
              supportedFeature = false;
            }
          } else {
            supportedFeature = false;
          }
        }
      }
      // If the feature is not supported by the browser, then add it to polyfill it
      if (supportedFeature === false) {
        arrayUnsupportedFeatures.push(fullFeature);
      }
    }
    return arrayUnsupportedFeatures;
  }
docs: Check each feature in the featureString parameter (comma separated) and returns an array with all unsupported features for the current browser