code: def get_global_ensemble_model(output_chunk_length=5):
      lags = [-1, -2, -5]
      return NaiveEnsembleModel(
          forecasting_models=[
              LinearRegressionModel(
                  lags=lags,
                  lags_past_covariates=lags,
                  output_chunk_length=output_chunk_length,
              ),
              LinearRegressionModel(
                  lags=lags,
                  lags_past_covariates=lags,
                  output_chunk_length=output_chunk_length,
              ),
          ],
      )
  
imports: import numpy
  import pandas
  import pytest
  from darts import TimeSeries
  from darts.logging import get_logger
  from darts.models import ExponentialSmoothing, LinearRegressionModel, NaiveDrift, NaiveEnsembleModel, NaiveSeasonal, StatsForecastAutoARIMA, Theta
  from darts.tests.conftest import tfm_kwargs
  from darts.utils import timeseries_generation
label_desc: Use image node_id 22 for calling the TestEnsembleModels obj's underlying member method code with example usage: obj.get_global_ensemble_model(output_chunk_length) and returns: NaiveEnsembleModel