code: def df():
      data = generate_df_with_reg_for_tests(
          freq="D",
          periods=20 * 7,
          train_frac=0.9,
          remove_extra_cols=True,
          mask_test_actuals=True,
      )
      reg_cols = ["regressor1", "regressor2", "regressor3"]
      keep_cols = [TIME_COL, VALUE_COL] + reg_cols
      df = data["df"][keep_cols]
      return df
  
imports: import pickle
  import sys
  import numpy
  import pandas
  import pytest
  from plotly.colors import DEFAULT_PLOTLY_COLORS
  from greykite.algo.forecast.silverkite.constants.silverkite_holiday import SilverkiteHoliday
  from greykite.common.constants import ACTUAL_COL
  from greykite.common.constants import PREDICTED_COL
  from greykite.common.constants import PREDICTED_LOWER_COL
  from greykite.common.constants import PREDICTED_UPPER_COL
  from greykite.common.constants import TIME_COL
  from greykite.common.constants import VALUE_COL
  from greykite.common.evaluation import EvaluationMetricEnum
  from greykite.common.evaluation import root_mean_squared_error
  from greykite.common.python_utils import assert_equal
  from greykite.common.testing_utils import generate_df_with_reg_for_tests
  from greykite.framework.benchmark.benchmark_class import BenchmarkForecastConfig
  from greykite.framework.constants import FORECAST_STEP_COL
  from greykite.framework.templates.autogen.forecast_config import ComputationParam
  from greykite.framework.templates.autogen.forecast_config import EvaluationMetricParam
  from greykite.framework.templates.autogen.forecast_config import EvaluationPeriodParam
  from greykite.framework.templates.autogen.forecast_config import ForecastConfig
  from greykite.framework.templates.autogen.forecast_config import MetadataParam
  from greykite.framework.templates.autogen.forecast_config import ModelComponentsParam
  from greykite.framework.templates.forecaster import Forecaster
  from greykite.framework.templates.model_templates import ModelTemplateEnum
  from greykite.sklearn.cross_validation import RollingTimeSeriesSplit
label_desc: Use image node_id 1 for calling a global function with example usage: df() and returns: df