anchor.diff:  %% magic number that indicates a bookshelf file.
   -define(BKSF_IND, 16#0DDBA11).
   
  -%% The total header size
  --define(BKSF_HEADER_SIZE, (4 + 14 + 32)).
  +%% Header Information
  +-define(BKSF_HEADER_SIZE, (4 + 2)).
  +
  +-define(BKSF_VERSION, 1).
  +-define(BKSF_HEADER_DETAIL_SIZE_1, (14 + 32)).
  +
  +-define(CURRENT_HEADER_SIZE,
  +        (?BKSF_HEADER_SIZE + ?BKSF_HEADER_DETAIL_SIZE_1)).
   
   %% This FILE_PAD is appended to the front of files.
  --define(FILE_PAD, <<?BKSF_IND:32,
  +-define(FILE_PAD, <<?BKSF_IND:32, 0:16,
                       0,0,0,0,0,0,0,0,0,0,
                       0,0,0,0,0,0,0,0,0,0,
                       0,0,0,0,0,0,0,0,0,0,
  
positive.code: obj_close({File, Ctx}) ->
      FinalMD5 = erlang:md5_final(Ctx),
      %% The first four bytes are the BKSF indicator
      {ok, 4} = file:position(File, 4),
      file:write(File, create_timestamp()),
      file:write(File, to_hex(FinalMD5)),
      case file:close(File) of
          ok  ->
              {ok, FinalMD5};
  
negative.code:     {ok, CpySize} =
          file:copy(filename:join([Dir, encode(FromBucket), encode(FromPath)]),
                    filename:join([Dir, encode(ToBucket), encode(ToPath)])),
      {State, {ok, CpySize - ?CURRENT_HEADER_SIZE}}.
  
  -spec obj_send(fs_data(), bkss_store:bucket_name(),
                 bkss_store:path(), Trans::bkss_transport:trans()) ->
  