'The changes passed to ``in_parallel`` are run in parallel (that is,
they are all started before any of them completes) by
``run_state_changes``.'

def test_in_parallel(self):

    subchanges = [ControllableAction(result=Deferred()), ControllableAction(result=succeed(None))]
    change = in_parallel(changes=subchanges)
    run_state_change(change, DEPLOYER, InMemoryStatePersister())
    called = [subchanges[0].called, subchanges[1].called]
    self.assertEqual(called, [True, True])
