SAML2\XML\saml\SubjectConfirmationTest::testManyNameIDThrowsException PHP Method

    public function testManyNameIDThrowsException()
    {
        $samlNamespace = Constants::NS_SAML;
        $document = DOMDocumentFactory::fromString(<<<XML
<saml:SubjectConfirmation xmlns:saml="{$samlNamespace}" Method="SomeMethod">
  <saml:NameID>SomeNameIDValue</saml:NameID>
  <saml:NameID>AnotherNameIDValue</saml:NameID>
  <saml:SubjectConfirmationData/>
</saml:SubjectConfirmation>
XML
);
        $this->setExpectedException('Exception', 'More than one NameID in a SubjectConfirmation element');
        $subjectConfirmation = new SubjectConfirmation($document->firstChild);
    }