public void LikeButton_Method()
        {
            Assert.Throws <ArgumentNullException>(() => IFacebookHtmlHelperExtensions.LikeButton(null, widget => { }));
            Assert.Throws <ArgumentNullException>(() => new FacebookHtmlHelper().LikeButton(null));

            Assert.Equal(new FacebookHtmlHelper().LikeButton().ToHtmlString(), new FacebookHtmlHelper().LikeButton(x => { }));
            Assert.Equal(new FacebookHtmlHelper().LikeButton().Url("url").ToHtmlString(), new FacebookHtmlHelper().LikeButton(x => x.Url("url")));
        }
        public void Video_Method()
        {
            Assert.Throws <ArgumentNullException>(() => IFacebookHtmlHelperExtensions.Video(null, widget => { }));
            Assert.Throws <ArgumentNullException>(() => new FacebookHtmlHelper().Video(null));

            Assert.Equal(new FacebookHtmlHelper().Video().ToHtmlString(), new FacebookHtmlHelper().Video(x => { }));
            Assert.Equal(new FacebookHtmlHelper().Video().Id("id").ToHtmlString(), new FacebookHtmlHelper().Video(x => x.Id("id")));
        }
        public void RecommendationsFeed_Method()
        {
            Assert.Throws <ArgumentNullException>(() => IFacebookHtmlHelperExtensions.RecommendationsFeed(null, widget => { }));
            Assert.Throws <ArgumentNullException>(() => new FacebookHtmlHelper().RecommendationsFeed(null));

            Assert.Equal(new FacebookHtmlHelper().RecommendationsFeed().ToHtmlString(), new FacebookHtmlHelper().RecommendationsFeed(x => { }));
            Assert.Equal(new FacebookHtmlHelper().RecommendationsFeed().Domain("domain").ToHtmlString(), new FacebookHtmlHelper().RecommendationsFeed(x => x.Domain("domain")));
        }
        public void Initialize_Method()
        {
            Assert.Throws <ArgumentNullException>(() => IFacebookHtmlHelperExtensions.Initialize(null, widget => { }));
            Assert.Throws <ArgumentNullException>(() => new FacebookHtmlHelper().Initialize(null));

            Assert.Equal(new FacebookHtmlHelper().Initialize().ToHtmlString(), new FacebookHtmlHelper().Initialize(x => { }));
            Assert.Equal(new FacebookHtmlHelper().Initialize().AppId("appId").ToHtmlString(), new FacebookHtmlHelper().Initialize(x => x.AppId("appId")));
        }