public IHttpActionResult GetStudentsByGradeDates([FromUri] DateTime d1, [FromUri] DateTime d2)
        {
            string role = ((ClaimsPrincipal)RequestContext.Principal).FindFirst(x => x.Type == ClaimTypes.Role).Value;

            try
            {
                switch (role)
                {
                case "admin":
                    string adminId = ((ClaimsPrincipal)RequestContext.Principal).FindFirst(x => x.Type == "UserId").Value;
                    logger.Info("Calling admin access level StudentsService method GetAllByGradeDates. Admin ID: {0}", adminId);
                    var retVal1 = service.GetAllByGradeDates(d1, d2);
                    logger.Info("Returning ok to browser.");
                    return(Ok(retVal1));

                case "teacher":
                    string teacherId = ((ClaimsPrincipal)RequestContext.Principal).FindFirst(x => x.Type == "UserId").Value;
                    logger.Info("Calling teacher access level StudentsService method GetAllByGradeDatesAndTeacherId. Teacher ID: {0}", teacherId);
                    var retVal2 = service.GetAllByGradeDatesAndTeacherId(d1, d2, teacherId);
                    logger.Info("Returning ok to browser.");
                    return(Ok(retVal2));

                default:
                    logger.Warn("BadRequest. There is no method for this role! {0}", role);
                    return(BadRequest());
                }
            }
            catch (Exception e)
            {
                logger.Warn("Caught exception with message {0}. Returning bad request.", e.Message);
                return(BadRequest(e.Message));
            }
        }