ShouldContains not throwing if no element found

Hi,

I have a unit test which looks something like the following:

BrowserResponse response = Browser.Post("/forgotpassword", with =>

{

with.FormValue("email", "doesno...@somewhere.com");

with.HttpsRequest();

});

Assert.Equal(HttpStatusCode.OK, response.StatusCode);

response.Body["#alert-error"].ShouldContain("Sorry, can't find that email address"); // <<< This doesn't throw

I was trying to get a failing test first so I just returned status code 200, expecting that the ShouldContain line would throw. But it doesn't, because there is no #alert-error element. Is this expected behaviour? I would've thought it should throw.

Happy to send a pull request, just want to be sure it wouldn't break things first

Cheers,

Andrew