anchor.diff:  
   %% @doc Selects the appropriate decoder for a message code.
   -spec decoder_for(pos_integer()) -> module().
  -decoder_for(N) -> 
  +decoder_for(N) ->
       riak_pb_messages:decoder_for(N).
   
   %% @doc Selects the appropriate PB encoder for a given message name.
  
positive.code: %% return the atom for the message code. Replaces `riakc_pb:decode/2'.
  
  -spec decode(integer(), binary()) -> atom() | tuple().
  decode(MsgCode, MsgData) ->
      Decoder = decoder_for(MsgCode),
      Decoder:decode(msg_type(MsgCode), MsgData).
  
negative.code: 
  %% ------------------------------------------------------------
  %% Encode a message when no content body is present (message atom
  %% only).
  %%
  %% For PB messages, this simply encodes the message code, which serves
  %% to identify the encoded message on the other side of the socket
  %% connection.
  