code: def test_start_freq_holtwinters(frequency, start_periods):
      global airpassengers, co2, nybirths
      data = np.asarray(
          [airpassengers, co2, nybirths], dtype=np.float64
      )
      cu_hw = cuml_ES(
          data,
          ts_num=3,
          seasonal_periods=frequency,
          start_periods=start_periods,
      )
      cu_hw.fit()
      cu_hw.forecast(5)
  
file_path: cuml/python/cuml/tests/test_holtwinters.py
imports: from sklearn.metrics import r2_score
  from statsmodels.tsa.holtwinters import ExponentialSmoothing
  from cuml.tsa.holtwinters import ExponentialSmoothing
  import pytest
  from cuml.internals.safe_imports import cpu_only_import
label_desc: Use image node_id 5 for calling a global function with example usage: test_start_freq_holtwinters(frequency, start_periods) without return types