anchor.diff:  
   Scanned block section::
     The section is named so because it contains all data blocks that need to be read when an HFile is scanned sequentially.
  -  Also contains leaf block index and Bloom chunk blocks.
  +  Also contains Leaf index blocks and Bloom chunk blocks.
   Non-scanned block section::
     This section still contains unified-format v2 blocks but it does not have to be read when doing a sequential scan.
     This section contains "meta" blocks and intermediate-level index blocks.
  
positive.code: 
  . Data index -- version 2 multi-level block index, consisting of:
  .. Version 2 root index, stored in the data block index section of the file
  .. Optionally, version 2 intermediate levels, stored in the non%root format in   the data index section of the file. Intermediate levels can only be present if leaf level blocks are present
  .. Optionally, version 2 leaf levels, stored in the non%root format inline with   data blocks
  . Meta index -- version 2 root index format only, stored in the meta index section of the file
  . Bloom index -- version 2 root index format only, stored in the ``load-on-open'' section as part of Bloom filter metadata.
  
  ==== Root block index format in version 2
  
  
negative.code: 
  . Offset (long)
  +
  This offset may point to a data block or to a deeper-level index block.
  
  . On-disk size (int)
  . Key (a serialized byte array stored using Bytes.writeByteArray)
  