private @NotNull("Seems accessed storage has been closed") PagedFileStorage getRegisteredPagedFileStorageByIndex(long storageId)
    throws ClosedStorageException {
    int storageIndex = (int)((storageId & FILE_INDEX_MASK) >> 32);
    synchronized (storageById) {
      PagedFileStorage storage = storageById.get(storageIndex);
      if (storage == null) {
        throw new ClosedStorageException("storage is already closed");
      }
      return storage;
    }
  }
private @NotNull("Seems accessed storage has been closed") PagedFileStorage getRegisteredPagedFileStorageByIndex(long storageId)