public void AllByPredicateExecutesReturnsFilteredResultsTest()
{
const string Html = @"
<html>
<head />
<body>
<form name='Test'>
<input type='text' name='Data' />
</form>
<form name='SecondTest'>
<input type='checkbox' name='IsSet' />
</form>
</body>
</html>
";
var page = new HtmlPageStub(Html);
var actual = page.Find<HtmlElement>().AllByPredicate(x => x is HtmlInput).ToList();
actual.Count.Should().Be(1);
actual[0].Should().BeAssignableTo<HtmlInput>();
}