code: def _get_univar_noexo_data_with_index_index():
      """Generates multiple datasets of univariate data without exogenous variables
      where the index has been set to various types of indices.
      """
      # PeriodIndex
      data1 = get_data("airline")
  
      # DatetimeIndex
      data2 = data1.copy()
      data2 = data2.to_timestamp()
  
      # Int64Index
      data3 = data1.copy()
      data3.reset_index(drop=True, inplace=True)
  
      ids = ["Period", "Datetime", "Int"]
  
      # DateTimeIndex is coerced and returned as PeriodIndex in PyCaret
      return [
          [
              (data1, pd.PeriodIndex),
              (data2, pd.PeriodIndex),
              (data3, pd.Index),
          ],
          ids,
      ]
  
file_path: pycaret/tests/test_time_series_indices.py
imports: import os
  from typing import Any
  import pandas
  import pytest
  from pycaret.datasets import get_data
  from pycaret.time_series import TSForecastingExperiment
label_desc: Use image node_id 1 for calling a global function with example usage: _get_univar_noexo_data_with_index_index() and returns: list