private boolean isRootDirChange(@NotNull VFileEvent event) {
    VirtualFile file = event.getFile();
    if (file == null) return true; // can't do fast check, fallback to paths matching
    for (VirtualFile dir : myRootDirs) {
      if (VfsUtilCore.isAncestor(dir, file, false)) return true;
    }
    return false;
  }
private boolean isRootDirChange(@NotNull VFileEvent event)