'Test an error with assertIsInstance and multiple classes.'

def test_assertIsInstanceErrorMultipleClasses(self):

    A = type('A', (object,), {})
    B = type('B', (object,), {})
    C = type('C', (object,), {})
    a = A()
    self.assertRaises(self.failureException, self.assertIsInstance, a, (B, C))
