public async Task <FilledQuestionnaireResponse> GetAnsweredQuestionnaireAsync(string clientId)
        {
            var questionsTask = _questionnaireService.GetQuestionnaireAsync(clientId);
            var rankTask      = _questionnaireService.GetQuestionnaireRankAsync(clientId);

            await Task.WhenAll(questionsTask, rankTask);

            var result = new FilledQuestionnaireResponse
            {
                Questionnaire = _mapper.Map <AnsweredQuestionModel[]>(questionsTask.Result),
                Rank          = rankTask.Result?.Rank ?? 0
            };

            return(result);
        }