code: def _generate_new_dates(
      n: int,
      input_series: TimeSeries,
      start: Optional[Union[pd.Timestamp, int]] = None,
  ) -> Union[pd.DatetimeIndex, pd.RangeIndex]:
      """
      Generates `n` new dates after the end of the specified series
      """
      if start is None:
          last = input_series.end_time()
          start = last + input_series.freq
      return generate_index(
          start=start,
          freq=input_series.freq,
          length=n,
          name=input_series.time_dim,
      )
  
file_path: darts/darts/utils/timeseries_generation.py
imports: import math
  from typing import List, Optional, Sequence, Tuple, Union
  import holidays
  import numpy
  import pandas
  from darts import TimeSeries
  from darts.logging import get_logger, raise_if, raise_if_not, raise_log
label_desc: Use image node_id 12 for calling a global function with example usage: _generate_new_dates(n, input_series, start) and returns: generate_index