public static void check(
     ProjectStructureElement element, ProjectStructureProblemsHolder problemsHolder) {
   for (ProjectStructureValidator validator : EP_NAME.getExtensions()) {
     if (validator.checkElement(element, problemsHolder)) {
       return;
     }
   }
   element.check(problemsHolder);
 }
 public static List<ProjectStructureElementUsage> getUsagesInElement(
     final ProjectStructureElement element) {
   for (ProjectStructureValidator validator : EP_NAME.getExtensions()) {
     List<ProjectStructureElementUsage> usages = validator.getUsagesIn(element);
     if (usages != null) {
       return usages;
     }
   }
   return element.getUsagesInElement();
 }