anchor.diff:  %% return the atom for the message code. Replaces `riakc_pb:decode/2'.
   
   -spec decode(integer(), binary()) -> atom() | tuple().
  +-decode(MsgCode, <<>>) ->
  +    msg_type(MsgCode);
   decode(MsgCode, MsgData) ->
       Decoder = decoder_for(MsgCode),
       Decoder:decode(msg_type(MsgCode), MsgData).
  
positive.code: 
  %% @doc Selects the appropriate decoder for a message code.
  -spec decoder_for(pos_integer()) -> module().
  decoder_for(N) -> 
      riak_pb_messages:decoder_for(N).
  
  %% @doc Selects the appropriate PB encoder for a given message name.
  
negative.code: %% @doc Converts a message code into the symbolic message
  %% name. Replaces `riakc_pb:msg_type/1'.
  -spec msg_type(integer()) -> atom().
  msg_type(Int) ->
      riak_pb_messages:msg_type(Int).
  
  %% @doc Converts a symbolic message name into a message code. Replaces
  