@RequiresWriteLock
  private void clearViewProviders() {
    DebugUtil.performPsiModification("clearViewProviders", () -> {
      ConcurrentMap<VirtualFile, FileViewProvider> map = myVFileToViewProviderMap.get();
      if (map != null) {
        for (FileViewProvider viewProvider : map.values()) {
          markInvalidated(viewProvider);
        }
      }
      myVFileToViewProviderMap.set(null);
    });
  }
@RequiresWriteLock
  private void clearViewProviders()