code: def _get_period_diff_as_int(
      x: pd.PeriodIndex, y: pd.PeriodIndex
  ) -> pd.Index:
      return x.astype("int64") - y.astype("int64")
  
file_path: sktime/sktime/transformations/series/time_since.py
imports: from __future__ import annotations
  import datetime
  import warnings
  from string import digits
  import numpy
  import pandas
  from pandas.tseries.frequencies import get_period_alias
  from sktime.transformations.base import BaseTransformer
label_desc: Use image node_id 1 for calling a global function with example usage: _get_period_diff_as_int(x, y) and returns: unknown