private void checkFileIdValid(int fileId) {
    if (checkFileIdsBelowMax) {
      int maxAllocatedID = maxAllocatedFileID();
      if (fileId < FSRecords.ROOT_FILE_ID || fileId > maxAllocatedID) {
        throw new IllegalArgumentException(
          "fileId[#" + fileId + "] is outside of allocated range [" + FSRecords.ROOT_FILE_ID + ".." + maxAllocatedID + "]");
      }
    }
    else {
      if (fileId < FSRecords.ROOT_FILE_ID) {
        throw new IllegalArgumentException(
          "fileId[#" + fileId + "] is invalid, must be >=" + FSRecords.ROOT_FILE_ID);
      }
    }
  }
private void checkFileIdValid(int fileId)