@Test(expected = WrongReferenceAttributeValueException.class)
public void testCheckWithPreferredValueButNoCertificates() throws Exception {

	System.out.println("testCheckWithPreferredValueButNoCertificates()");
	reqAttribute.setValue(null);
	attributeToCheck.setValue("example");
	classInstance.checkAttributeSemantics(session, user, attributeToCheck);
}