code: def test_get_anomaly_df_from_outliers1():
      """Tests `get_anomaly_df_from_outliers` when no outlier exists."""
      value_col = "y"
      freq = "H"
  
      # No outlier in Series - returns empty `pd.DataFrame` with columns `START_TIME_COL`, `END_TIME_COL`.
      df = pd.DataFrame(
          {
              TIME_COL: pd.date_range(
                  start="2020-01-01",
                  end="2020-02-11 16:00:00",
                  freq=freq,
              ),
              value_col: [2] * 1001,
          }
      )
      empty_anomaly_df = pd.DataFrame(
          columns=[START_TIME_COL, END_TIME_COL]
      )
      anomaly_df = get_anomaly_df_from_outliers(
          df=df, time_col=TIME_COL, value_col=value_col, freq=freq
      )
      assert_equal(anomaly_df, empty_anomaly_df)
  
imports: import itertools
  import numpy
  import pandas
  import pytest
  from testfixtures import LogCapture
  from greykite.common.constants import ANOMALY_COL
  from greykite.common.constants import END_TIME_COL
  from greykite.common.constants import LOGGER_NAME
  from greykite.common.constants import START_TIME_COL
  from greykite.common.constants import TIME_COL
  from greykite.common.constants import TimeFeaturesEnum
  from greykite.common.testing_utils import assert_equal
  from greykite.detection.detector.ad_utils import add_new_params_to_records
  from greykite.detection.detector.ad_utils import get_anomaly_df
  from greykite.detection.detector.ad_utils import get_anomaly_df_from_outliers
  from greykite.detection.detector.ad_utils import get_canonical_anomaly_df
  from greykite.detection.detector.ad_utils import get_timestamp_ceil
  from greykite.detection.detector.ad_utils import get_timestamp_floor
  from greykite.detection.detector.ad_utils import optimize_df_with_constraints
  from greykite.detection.detector.ad_utils import partial_return
  from greykite.detection.detector.ad_utils import validate_volatility_features
  from greykite.detection.detector.ad_utils import vertical_concat_dfs
label_desc: Use image node_id 11 for calling a global function with example usage: test_get_anomaly_df_from_outliers1() without return types