func (s *storeManagerStateSuite) TestChanged(c *C) {
	collections := map[string]*mgo.Collection{
		"machines":    s.State.machines,
		"units":       s.State.units,
		"services":    s.State.services,
		"relations":   s.State.relations,
		"annotations": s.State.annotations,
		"statuses":    s.State.statuses,
		"constraints": s.State.constraints,
		"settings":    s.State.settings,
	}
	for i, test := range allWatcherChangedTests {
		c.Logf("test %d. %s", i, test.about)
		b := newAllWatcherStateBacking(s.State)
		all := multiwatcher.NewStore()
		for _, info := range test.add {
			all.Update(info)
		}
		test.setUp(c, s.State)
		c.Logf("done set up")
		ch := test.change
		ch.C = collections[ch.C].Name
		err := b.Changed(all, test.change)
		c.Assert(err, IsNil)
		assertEntitiesEqual(c, all.All(), test.expectContents)
		s.Reset(c)
	}
}
func (s *storeManagerStateSuite) TestStateBackingGetAll(c *C) {
	expectEntities := s.setUpScenario(c)
	b := newAllWatcherStateBacking(s.State)
	all := multiwatcher.NewStore()
	err := b.GetAll(all)
	c.Assert(err, IsNil)
	var gotEntities entityInfoSlice = all.All()
	sort.Sort(gotEntities)
	sort.Sort(expectEntities)
	assertEntitiesEqual(c, gotEntities, expectEntities)
}