public IHttpActionResult AddSlide([FromBody] SlideDto slideDto)
        {
            try
            {
                if (!ModelState.IsValid)
                {
                    return(BadRequest(ModelState));
                }

                var result = _slideService.AddSlide(slideDto);
                if (result == null)
                {
                    return(BadRequest("An error occurred when adding slide. Please try again."));
                }
                return(Ok(result));
            }
            catch (System.Exception e)
            {
                return(InternalServerError(e));
            }
        }