'An update for previously given hostname overrides the previous state
of that hostname.'

def test_update(self):

    service = self.service()
    service.apply_changes([NodeState(hostname=u'host1', applications={APP1.name: APP1}), NodeState(hostname=u'host1', applications={APP2.name: APP2})])
    self.assertEqual(service.as_deployment(), DeploymentState(nodes=[NodeState(hostname=u'host1', applications={APP2.name: APP2})]))
