new HandleUnknownAtRuleNodes(cssTree.getMutatingVisitController(), errorManager,
allowedAtRules, true, false).runPass();
new ProcessKeyframes(cssTree.getMutatingVisitController(), errorManager, true, true).runPass();
new ProcessRefiners(cssTree.getMutatingVisitController(), errorManager, true).runPass();
PermutationsCollector permutationsCollector = new PermutationsCollector(cssTree
.getMutatingVisitController(), errorManager);
permutationsCollector.runPass();
return permutationsCollector.getPermutationAxes();
}