'Test that flattening a slot will use the slot value from the tag.'

def test_serializeSlots(self):

    t1 = tags.p(slot('test'))
    t2 = t1.clone()
    t2.fillSlots(test='hello,    world')
    return gatherResults([self.assertFlatteningRaises(t1, UnfilledSlot), self.assertFlattensTo(t2, '<p>hello,    world</p>')])
