private static (AspNetSessionValueLayoutRenderer, HttpContext) CreateRenderer(bool throwsError = false)
        {
            var(renderer, httpContext) = CreateWithHttpContext();

            var mockSession = new SessionMock(throwsError);

            mockSession.SetString("a", "https://duckduckgo.com");
            mockSession.SetInt32("b", 123);
            httpContext.Session = mockSession;
            httpContext.Items   = new Dictionary <object, object>();
            var sessionFeature = new SessionFeatureMock(mockSession);

            httpContext.Features.Get <ISessionFeature>().Returns(sessionFeature);
            return(renderer, httpContext);
        }