anchor.diff:    DataBytes = make_block(Header, Objects),
     [HeaderBytes, DataBytes].
   
  -%%%_* Internal functions =======================================================
  -
  +%% @doc Encode the given ocf header.
   -spec encode_header(header()) -> iodata().
   encode_header(Header) ->
     HeaderFields =
  
positive.code:   , Data
    , Header#header.sync
    ].
  
  %% Raise an exception if meta has a bad format.
  %% Otherwise return the formatted metadata entries
  
negative.code:   HeaderRecord = avro_record:new(ocf_schema(), HeaderFields),
    avro_binary_encoder:encode_value(HeaderRecord).
  
  %% @doc Encode the given objects as one data block.
  -spec make_block(header(), [binary()]) -> iodata().
  make_block(Header, Objects) ->
    Count = length(Objects),
  