'If era information was not known, ``UpdateNodeStateEra`` adds it.'

def test_no_era(self):

    state = self.UPDATE_ERA_1.update_cluster_state(self.INITIAL_CLUSTER)
    self.assertEqual(state, self.INITIAL_CLUSTER.transform(['node_uuid_to_era', self.UPDATE_ERA_1.uuid], self.UPDATE_ERA_1.era))
