@VisibleForTesting
  static long recordOffsetToId(long recordOffset) {
    AlignmentUtils.assert32bAligned(recordOffset, "recordOffsetInFile");
    //recordOffset is int32-aligned, 2 lowest bits are 0, we could drop them, and make recordId smaller
    //0 is considered invalid id (NULL_ID) everywhere in our code, so '+1' for first id to be 1
    return ((recordOffset - HeaderLayout.HEADER_SIZE) >> 2) + 1;
  }
@VisibleForTesting
  static long recordOffsetToId(long recordOffset)