code: def df_panel():
      """Create panel data of two time series using pd-multiindex mtype."""
      return _make_hierarchical(
          hierarchy_levels=(2,), min_timepoints=3, max_timepoints=3
      )
  
imports: import numpy
  import pandas
  import pytest
  from pandas.testing import assert_frame_equal
  from sktime.datasets import load_airline, load_longley, load_PBS_dataset
  from sktime.split import temporal_train_test_split
  from sktime.tests.test_switch import run_test_for_class
  from sktime.transformations.series.date import DateTimeFeatures
  from sktime.utils._testing.hierarchical import _make_hierarchical
label_desc: Use image node_id 23 for calling a global function with example usage: df_panel() and returns: _make_hierarchical