anchor.diff:    ActualResponse   = request(Request),
     case Result = validate(ExpectedResponse, ActualResponse) of
       pass -> run_scenario(T, Params, SubVars, [{Request, Result}|Acc]);
  -    _    -> dbg(Request, ExpectedResponse, ActualResponse, Result)
  +    _    -> dbg(Description, Request, ExpectedResponse, ActualResponse, Result)
     end;
   run_scenario([], _, _, Acc) ->
     Acc.
  
positive.code:                 ).
  
  
  dbg(Request, ExpectedResponse, ActualResponse, Result) ->
    ct:pal("Request:~n~p~n~n"
           "Expected response:~n~p~n~n"
           "Actual response:~n~p~n~n"
           "Result:~n~p~n~n",
           [Request, ExpectedResponse, ActualResponse, Result]).
  
  substitute(Bin, [])         -> Bin;
  substitute(Bin, [{K, V}|T]) -> substitute(substitute(Bin, K, V), T).
  
negative.code: run_scenario(Blueprint, Params, SubVars) ->
    run_scenario(Blueprint#api_blueprint.operations, Params, SubVars, []).
  
  run_scenario( [#katt_operation{ description=Description
                                , request=Req
                                , response=Rsp
                                }|T]
              , Params
              , SubVars
              , Acc
  