code: def test_manspec_with_tsfreq_step_output():
      return [
          "GNPDEFL",
          "GNP",
          "UNEMP",
          "ARMED",
          "POP",
          "year",
          "second_of_minute",
      ]
  
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 9 for calling a global function with example usage: test_manspec_with_tsfreq_step_output() and returns: list