anchor.diff:          {ok, 200, _RespHeaders, RespBody} ->
               UserCtx = json_utils:decode_map(RespBody),
               case helper:validate_user_ctx(Helper, UserCtx) of
  -                ok -> {ok, UserCtx};
  +                ok -> {ok, ensure_binary_values(UserCtx)};
                   {error, Reason} -> {error, Reason}
               end;
           {ok, Code, _RespHeaders, RespBody} ->
  
positive.code:                 <<"emailList">> => []
              }
      end.
  
negative.code:             GroupCtx = json_utils:decode_map(RespBody),
              case helper:validate_group_ctx(Helper, GroupCtx) of
                  ok ->
                      {ok, ensure_binary_values(GroupCtx)};
                  Error = {error, Reason} ->
                      ?error_stacktrace("Invalid group ctx returned from map_group request: ~p", [Reason]),
                      Error
  