code: def to_labels(
      lists: List[
          Union[Tuple[pd.Timestamp, pd.Timestamp], pd.Timestamp]
      ],
      time_index: pd.DatetimeIndex,
      freq_as_period: bool = True,
  ) -> pd.Series:
      ...
  
file_path: adtk/src/adtk/data/_data.py
imports: from typing import Dict, List, Optional, Tuple, Union, overload
  import numpy
  import pandas
label_desc: Use image node_id 6 for calling a global function with example usage: to_labels(lists, time_index, freq_as_period) without return types