if (eliminateDeadStyles) {
// Report errors for duplicate declarations
new DisallowDuplicateDeclarations(cssTree.getVisitController(), errorManager).runPass();
// Split rules by selector and declaration.
new SplitRulesetNodes(cssTree.getMutatingVisitController()).runPass();
// Dead code elimination.
new MarkRemovableRulesetNodes(cssTree).runPass();
new EliminateUselessRulesetNodes(cssTree).runPass();
// Merge of rules with same selector.
new MergeAdjacentRulesetNodesWithSameSelector(cssTree).runPass();