* renaming for these classes. We cannot collect the external classes during the original renaming
* because some external at-rule could be located inside a conditional block and could be
* removed when these blocks are evaluated.
*/
private Set<String> revertRenamingOfExternalClasses(CssTree cssTree, RenamingResult renamingResult) {
ExternalClassesCollector externalClassesCollector = new ExternalClassesCollector(cssTree
.getMutatingVisitController(), errorManager);
externalClassesCollector.runPass();
Map<String, String> styleClassesMapping = renamingResult.mapping;
// set containing all the style classes before the renaming.
Set<String> allStyleClassSet = Sets.newHashSet(styleClassesMapping.keySet());
// add the style classes that aren't associated to a method
allStyleClassSet.addAll(renamingResult.externalClassCandidate);
Set<String> externalClasses = externalClassesCollector.getExternalClassNames(allStyleClassSet,
renamingResult.externalClassCandidate);
final Map<String, String> revertMap = new HashMap<String, String>(externalClasses.size());
for (String external : externalClasses) {