public async Task <IActionResult> GetPageById(int id)
        {
            if (id <= 0)
            {
                ProblemDetails problem = new ProblemDetails
                {
                    Title    = "Invalid id specified.",
                    Detail   = "The specified id is invalid.",
                    Instance = "C204ED32-70A4-498D-9EB2-A73EF69F4DA0"
                };
                return(BadRequest(problem));
            }

            WizardPage page = await wizardPageService.FindAsync(id);

            if (page == null)
            {
                ProblemDetails problem = new ProblemDetails
                {
                    Title  = "Failed getting the wizard page.",
                    Detail =
                        "The database does not contain a wizard page with the specified id.",
                    Instance = "E562B217-5847-4429-B61B-FAF1F8B33975"
                };
                return(NotFound(problem));
            }

            WizardPageResourceResult model = mapper.Map <WizardPage, WizardPageResourceResult>(page);

            return(Ok(model));
        }