private void refreshPostponedRoots() {
   for (VirtualFile root : safeGetAndClear(myRootsToRefresh)) {
     myDataHolder.refresh(root); // TODO support batch root refresh
   }
   for (VirtualFile root : safeGetAndClear(myRootsToRefreshRefs)) {
     myDataHolder.refreshRefs(root); // TODO support batch root refresh
   }
 }
 @Override
 public void refreshRefs(@NotNull VirtualFile root) {
   if (isOurContentPaneShowing()) {
     myDataHolder.refreshRefs(root);
   } else {
     synchronized (REFRESH_LOCK) {
       myRootsToRefreshRefs.add(root);
     }
   }
 }