public IHttpActionResult PostSlideBefore(Guid slideshowId, Guid slideId, SlideInputModel model)
        {
            if (slideshowId == null || slideId == null)
            {
                return NotFound();
            }

            var slideshow = SlideshowRepository.Find(slideshowId);

            var referencedSlide = slideshow.Slides.FirstOrDefault(x => x.Id == slideId);

            if (slideshow == null || referencedSlide == null)
            {
                return NotFound();
            }

            var slide = new Slide(new Colour(model.BackgroundColourHexCode), Duration.From(model.DurationInSeconds), Transition.From(model.TransitionType), model.Name);

            if (model.IsActive)
            {
                slide.ActivateSlide();
            }
            else
            {
                slide.DeactivateSlide();
            }

            slideshow.InsertBefore(slide, referencedSlide);
            SlideshowRepository.Update(slideshow);

            return Created(new Uri(Url.Link("GetSlide", new { companyId = slideshow.CompanyId, slideshowId = slideshow.Id, slideId = slide.Id })), SlideModel.From(slide));
        }