code: def hourly_data():
      """Generate 500 days of hourly data for tests"""
      return generate_df_for_tests(
          freq="H",
          periods=24 * 500,
          train_start_date=datetime.datetime(2018, 7, 1),
          conti_year_origin=2018,
      )
  
file_path: greykite/greykite/tests/algo/forecast/silverkite/test_forecast_silverkite_helper.py
imports: import datetime
  import pandas
  import pytest
  from greykite.algo.forecast.silverkite.forecast_silverkite_helper import get_default_changepoints_dict
  from greykite.algo.forecast.silverkite.forecast_silverkite_helper import get_fourier_feature_col_names
  from greykite.algo.forecast.silverkite.forecast_silverkite_helper import get_silverkite_uncertainty_dict
  from greykite.algo.forecast.silverkite.forecast_silverkite_helper import get_similar_lag
  from greykite.common.features.timeseries_features import fourier_series_multi_fcn
  from greykite.common.python_utils import assert_equal
  from greykite.common.testing_utils import generate_df_for_tests
label_desc: Use image node_id 1 for calling a global function with example usage: hourly_data() and returns: generate_df_for_tests