public async Task <IHttpActionResult> AddAssessment([FromBody] AssessmentDTO assessmentModel)
        {
            if (!ModelState.IsValid)
            {
                return(BadRequest(ModelState));
            }

            var newAssessmentId = await AssessmentService.AddAssessmentAsync(assessmentModel);

            if (newAssessmentId != 0)
            {
                return(Ok(newAssessmentId));
            }
            else
            {
                return(NotFound());
            }
        }