if (simplifyCss) {
// Eliminate empty rules.
new EliminateEmptyRulesetNodes(cssTree.getMutatingVisitController()).runPass();
// Eliminating units for zero values.
new EliminateUnitsFromZeroNumericValues(cssTree.getMutatingVisitController()).runPass();
// Optimize color values.
new ColorValueOptimizer(cssTree.getMutatingVisitController()).runPass();
// Compress redundant top-right-bottom-left value lists.
new AbbreviatePositionalValues(cssTree.getMutatingVisitController()).runPass();
}