public ActionResult Generate(GenerateRectangleInput model)
        {
            if (!ModelState.IsValid)
            {
                return(View(model));
            }

            try
            {
                var grid = gridService.InitialiseWithRectanglesOfRandomSize(model.NumberOfRectangles);
                return(File(Encoding.UTF8.GetBytes(grid.ToStringUsingDimensionsOfRectangles()), "text/plain", "rectangle-dimensions.txt"));
            }
            catch (LogicException ex)
            {
                ModelState.AddLogicErrors(ex);
                return(View(model));
            }
        }
        public ActionResult Generate()
        {
            var model = new GenerateRectangleInput();

            return(View(model));
        }