private void validateEntryPoints() {
    long count = PsiManager.getInstance(myProject).getModificationTracker().getModificationCount();
    if (count != myLastModificationCount) {
      myLastModificationCount = count;
      Collection<SmartRefElementPointer> collection = myPersistentEntryPoints.values();
      SmartRefElementPointer[] entries =
          collection.toArray(new SmartRefElementPointer[collection.size()]);
      for (SmartRefElementPointer entry : entries) {
        RefElement refElement = (RefElement) entry.getRefElement();
        if (refElement != null && !refElement.isValid()) {
          myPersistentEntryPoints.remove(entry.getFQName());
        }
      }

      final Iterator<RefElement> it = myTemporaryEntryPoints.iterator();
      while (it.hasNext()) {
        RefElement refElement = it.next();
        if (!refElement.isValid()) {
          it.remove();
        }
      }
    }
  }