code: def test_seasonal_error(past_data, seasonality, expected):
      np.testing.assert_almost_equal(
          calculate_seasonal_error(
              past_data=past_data, freq=None, seasonality=seasonality
          ),
          expected,
      )
  
imports: import numpy
  import pytest
  from gluonts.evaluation.metrics import abs_error, abs_target_mean, abs_target_sum, calculate_seasonal_error, coverage, mape, mase, mse, msis, quantile_loss, smape
label_desc: Use image node_id 4 for calling a global function with example usage: test_seasonal_error(past_data, seasonality, expected) without return types