decorateRootNodeWithPlatformClasses function Null safety

void decorateRootNodeWithPlatformClasses(
  1. {List<Feature>? features,
  2. bool includeDefaults = true,
  3. Element? rootNode,
  4. dynamic callback(

    Appends CSS classes generated by getPlatformClasses to the specified rootNode.

    If you do not want defaultFeatureCssClassDecorators to be used, set includeDefaults to false.

    By default, rootNode is document.documentElement.


    void decorateRootNodeWithPlatformClasses(
        {List<Feature>? features,
        bool includeDefaults = true,
        Element? rootNode,
        callback()?}) {
      rootNode ??= document.documentElement;
      if (rootNode != null && !nodeHasBeenDecorated(rootNode)) {
        var existingClasses = rootNode.classes.toList();
        rootNode.className = getPlatformClasses(
            features: features,
            includeDefaults: includeDefaults,
            existingClasses: existingClasses);
        if (callback != null) callback();