anchor.diff:  
   -type packed_decode_fun() :: fun( (binary()) -> {any(), binary()} ).
   
  +-ifndef(EDOC).
   -spec parse_required_field/3 :: (
       Code :: pos_integer(),
       ParseValue :: decode_fun(),
  
positive.code:     end.
  
  
  -spec parse_record/1 :: (
      piqirun_buffer() ) -> [ parsed_field() ].
  
  
negative.code:     ParsePackedValue :: packed_decode_fun(),
      ParseValue :: decode_fun(),
      piqirun_buffer() ) -> [ any() ].
  -endif.
  
  
  parse_record({'block', Bytes}) ->
  