def test_content_driven_cache_wrap(self):
cache_name = self.check_cache_gone('content')
# Pass a non-empty list as content
cache = PersistentCache(cache_name, cache_manager=self.manager, contents=[''],
builder=lambda *args: [])
cache[0] = 'foo'
cache.append('bar')
cache.save()
cache.load()
self.assertTrue(isinstance(cache, PersistentCache))
self.assertTrue(isinstance(cache.contents, list))
self.check_cache(cache_name, True)
self.assertEqual(cache[0], 'foo')
self.assertEqual(cache[1], 'bar')
cache.invalidate_and_rebuild()
self.assertTrue(isinstance(cache, PersistentCache))
self.assertTrue(isinstance(cache.contents, list))
self.assert_contents_equal(cache, [])
