anchor.diff:  %% If the endpoint had a responding function defined, the state is set to the state returned by the function.
   %% @end
   %%--------------------------------------------------------------------
  --spec produce_mock_resp(Req :: cowboy_req:req(), ETSKey :: {Port :: integer(), Path :: binary()}) -> ok.
  +-spec produce_mock_resp(Req :: cowboy_req:req(), ETSKey :: {Port :: integer(), Path :: binary()}) -> {ok, cowboy_req:req()}.
   produce_mock_resp(Req, ETSKey) ->
       % Append the request to history
       [{?HISTORY_KEY, History}] = ets:lookup(?MAPPINGS_ETS, ?HISTORY_KEY),
  -    ets:delete_object(?MAPPINGS_ETS, {?HISTORY_KEY, History}),
       ets:insert(?MAPPINGS_ETS, {?HISTORY_KEY, History ++ [ETSKey]}),
       % Get the response term and current state by {Port, Path} key
       [{ETSKey, MappingState}] = ets:lookup(?MAPPINGS_ETS, ETSKey),
  
positive.code: start_listener(ListenerID, Port, Dispatch) ->
      % Save started listener in ETS
      [{?LISTENERS_KEY, ListenersList}] = ets:lookup(?MAPPINGS_ETS, ?LISTENERS_KEY),
      ets:delete_object(?MAPPINGS_ETS, {?LISTENERS_KEY, ListenersList}),
      ets:insert(?MAPPINGS_ETS, {?LISTENERS_KEY, ListenersList ++ [ListenerID]}),
      % Load certificates' paths from env
      {ok, CaCertFile} = application:get_env(?APP_NAME, ca_cert_file),
  
negative.code:                                    {_Response, _NewState} = Fun(Req, State)
                             end,
      % Put new state in the ETS
      ets:insert(?MAPPINGS_ETS, {ETSKey, MappingState#mapping_state{state = NewState, counter = Counter + 1}}),
      #mock_resp{code = Code, body = Body, content_type = CType, headers = Headers} = Response,
      {Port, Path} = ETSKey,
  