def test_store_and_access(self):
s = State()
p = PredicateInstance('happy', Instance('a'))
s.append(p)
self.assertEqual([p], s.fetch('happy', [Instance('a')]))
self.assertStateContains(PredicateInstance('happy', Instance('a')),
Evaluator(state=s))
def test_access_missing(self):
s = State()
self.assertEqual(s.fetch('happy', [Instance('a')]), [])
