anchor.diff:  	    {(Code - 16#100), Payload};
   
   	Code when Code >= 2#10100000 , Code < 2#11000000 ->
  -%	 101XXXXX for FixRaw 
  +%	 101XXXXX for FixRaw
   	    Len = Code rem 2#10100000,
   	    << Return:Len/binary, Remain/binary >> = Payload,
   	    {Return, Remain};
  
positive.code: % ===== internal APIs ===== %
  
  % positive fixnum
  pack_uint_(N) when is_integer( N ) , N < 128 ->  
      << 2#0:1, N:7 >>;
  % uint 8
  pack_uint_( N ) when is_integer( N ) andalso N < 256 ->
  
negative.code:     {more, pos_integer()} | {msgpack_term(), binary()} | {error, reason()}.
  unpack_(Flag, Payload)->
      PayloadLen = byte_size(Payload),
      case Flag of
  	16#C0 ->
  	    {nil, Payload};
  	16#C2 ->
  