def METHOD_NAME():
    strategy = SingleDeviceStrategy("cpu")
    optimizer = MockOptimizer()
    strategy.optimizers = [optimizer]
    assert isinstance(strategy.optimizers[0], MockOptimizer)
    assert isinstance(strategy._lightning_optimizers[0], LightningOptimizer)
    state = pickle.dumps(strategy)
    # dumping did not get rid of the lightning optimizers
    assert isinstance(strategy._lightning_optimizers[0], LightningOptimizer)
    strategy_reloaded = pickle.loads(state)
    # loading restores the lightning optimizers
    assert isinstance(strategy_reloaded._lightning_optimizers[0], LightningOptimizer)