CssTree cssTree = extendedCssTree.tree;
// Collect mixin definitions and replace mixins
CollectMixinDefinitions collectMixinDefinitions = new CollectMixinDefinitions(
cssTree.getMutatingVisitController(), errorManager);
collectMixinDefinitions.runPass();
new ReplaceMixins(cssTree.getMutatingVisitController(), errorManager,
collectMixinDefinitions.getDefinitions()).runPass();
new ProcessComponents<Object>(cssTree.getMutatingVisitController(), errorManager).runPass();