anchor.diff:          ok ->
               receive
                   ok -> ok;
  -                {error, Reason} -> {error, decode_rc(Reason)}
  +                {error, Reason} -> {error, Reason}
               end;
   
           Error ->
  
positive.code:         ok ->
              receive
                  {error, Reason} ->
                      {error, decode_rc(Reason)};
                  {ok, Stats} ->
                      {ok, Stats}
              end;
  
negative.code:         ok ->
              receive
                  {error, Reason} ->
                      {error, Reason};
                  {ok, Stats} ->
                      {ok, Stats}
              end;
  