public void ShouldThrowArgumentNullExceptionWhenAddedSelectorConfigureActionIsNull()
        {
            var cssClass = new CssClass("Button");

            Assert.Throws <ArgumentNullException>(() => cssClass.AddPseudoSelector(PseudoSelector.Active, null));
        }
        public void ShouldThrowArgumentNullExceptionWhenAddedSelectorIsNull()
        {
            var cssClass = new CssClass("Button");

            Assert.Throws <ArgumentNullException>(() => cssClass.AddPseudoSelector(null, p => p.WithStyle("test", "test")));
        }