code: def test_predictor(
      data,
      expected_output,
      prediction_length,
      season_length,
      imputation_method,
  ):
      prediction = get_prediction(
          data,
          prediction_length=prediction_length,
          season_length=season_length,
          imputation_method=imputation_method,
      )
      assert prediction.samples.shape == (1, prediction_length)
  
      np.testing.assert_equal(prediction.mean, expected_output)
  
imports: import numpy
  import pandas
  import pytest
  from gluonts.model.seasonal_naive import SeasonalNaivePredictor
  from gluonts.transform.feature import LastValueImputation, LeavesMissingValues
label_desc: Use image node_id 2 for calling a global function with example usage: test_predictor(data, expected_output, prediction_length, season_length, imputation_method) without return types