SAML2\AssertionTest::testMoreThanOneAuthnContextClassRefThrowsException PHP Method

    public function testMoreThanOneAuthnContextClassRefThrowsException()
    {
        $xml = <<<XML
<saml:Assertion xmlns:saml="urn:oasis:names:tc:SAML:2.0:assertion"
                ID="_593e33ddf86449ce4d4c22b60ac48e067d98a0b2bf"
                Version="2.0"
                IssueInstant="2010-03-05T13:34:28Z"
>
  <saml:Issuer>testIssuer</saml:Issuer>
  <saml:AuthnStatement AuthnInstant="2010-03-05T13:34:28Z">
    <saml:AuthnContext>
      <saml:AuthnContextClassRef>someAuthnContext</saml:AuthnContextClassRef>
      <saml:AuthnContextDeclRef>/relative/path/to/document.xml</saml:AuthnContextDeclRef>
      <saml:AuthnContextClassRef>someOtherAuthnContext</saml:AuthnContextClassRef>
    </saml:AuthnContext>
  </saml:AuthnStatement>
</saml:Assertion>
XML;
        $document = DOMDocumentFactory::fromString($xml);
        $this->setExpectedException('Exception', "More than one <saml:AuthnContextClassRef> in <saml:AuthnContext>");
        $assertion = new Assertion($document->firstChild);
    }