code: def test_localizer():
      dataset = ListDataset(
          data_iter=[
              {
                  "start": "2012-01-01",
                  "target": (np.zeros(20) + i * 0.1 + 0.01),
                  "id": f"{i}",
              }
              for i in range(3)
          ],
          freq="1H",
      )
  
      estimator = MeanEstimator(prediction_length=10, num_samples=50)
  
      local_pred = Localizer(estimator=estimator)
      agg_metrics, _ = backtest_metrics(
          test_dataset=dataset, predictor=local_pred
      )
  
imports: import numpy
  from gluonts.dataset.common import ListDataset
  from gluonts.evaluation import backtest_metrics
  from gluonts.model.predictor import Localizer, ParallelizedPredictor
  from gluonts.model.trivial.identity import IdentityPredictor
  from gluonts.model.trivial.mean import MeanEstimator
label_desc: Use image node_id 2 for calling a global function with example usage: test_localizer() without return types