private RenamingResult doClassRenaming(CssTree cssTree, JMethod method, TreeLogger logger,
ResourceContext context) throws UnableToCompleteException {
Map<String, Map<String, String>> replacementsWithPrefix = computeReplacements(method, logger,
context);
RenamingSubstitutionMap substitutionMap = new RenamingSubstitutionMap(replacementsWithPrefix);
new CssClassRenaming(cssTree.getMutatingVisitController(), substitutionMap, null).runPass();
Map<String, String> mapping = replacementsWithPrefix.get("");
mapping = Maps.newHashMap(Maps.filterKeys(mapping, Predicates.in(substitutionMap
.getStyleClasses())));
return new RenamingResult(mapping, substitutionMap.getExternalClassCandidates());
}