code: def test_remove_seasonality(self):
      # test default (naive) method
      calc_trend = remove_seasonality(self.ts, freq=6)
      diff = self.trend - calc_trend
      assert np.mean(diff.values() ** 2).item() < 0.5
  
      # test default (naive) method additive
      calc_trend = remove_seasonality(
          self.ts, freq=6, model=SeasonalityMode.ADDITIVE
      )
      diff = self.trend - calc_trend
      assert np.isclose(np.mean(diff.values() ** 2), 0.0)
  
      # test STL method
      calc_trend = remove_seasonality(
          self.ts,
          freq=6,
          method="STL",
          model=SeasonalityMode.ADDITIVE,
          low_pass=9,
      )
      diff = self.trend - calc_trend
      assert np.isclose(np.mean(diff.values() ** 2), 0.0)
  
      # check if error is raised
      with pytest.raises(ValueError):
          calc_trend = remove_seasonality(
              self.ts,
              freq=6,
              method="STL",
              model=SeasonalityMode.MULTIPLICATIVE,
          )
  
file_path: darts/darts/tests/utils/test_statistics.py
imports: import matplotlib.pyplot
  import numpy
  import pandas
  import pytest
  from darts import TimeSeries
  from darts.datasets import AirPassengersDataset
  from darts.utils.statistics import check_seasonality, extract_trend_and_seasonality, granger_causality_tests, plot_pacf, plot_residuals_analysis, remove_seasonality, remove_trend, stationarity_test_adf, stationarity_test_kpss, stationarity_tests
  from darts.utils.timeseries_generation import constant_timeseries, gaussian_timeseries, linear_timeseries
  from darts.utils.utils import ModelMode, SeasonalityMode
label_desc: Use image node_id 2 for calling the TestSeasonalDecompose obj's underlying member method code with example usage: obj.test_remove_seasonality() without return types