public void ByPredicateThrowsExceptionWithNullPredicateTest()
{
const string Html = @"
<html>
<head />
<body>
<form name='Test'>
<input type='text' id='DataId' name='Data' />
</form>
<form name='SecondTest'>
<input type='checkbox' name='IsSet' />
</form>
</body>
</html>
";
var page = new HtmlPageStub(Html);
Action action = () => page.Find<HtmlForm>().ByPredicate(null);
action.ShouldThrow<ArgumentNullException>();
}