'Test that when addChecker is called with a checker that
implements at least one of the interfaces our application
supports, it is successful.'

def test_canAddSupportedChecker(self):

    options = OptionsForUsernamePassword()
    options.addChecker(self.goodChecker)
    iface = options.supportedInterfaces[0]
    self.assertIdentical(options['credInterfaces'][iface][0], self.goodChecker)
    self.assertIdentical(options['credCheckers'][0], self.goodChecker)
    self.assertEqual(len(options['credInterfaces'][iface]), 1)
    self.assertEqual(len(options['credCheckers']), 1)
