private static void addAll(Object2IntMap<? super VirtualFile> entries,
                             VirtualFile[] files) {
    for (VirtualFile file : files) {
      if (!entries.containsKey(file)) {
        entries.put(file, entries.size());
      }
    }
  }
private static void addAll(Object2IntMap<? super VirtualFile> entries,
                             VirtualFile[] files)