code: def test_slice_dates(dates):
      """Test output of slice on dates."""
      slicer = slice("2011-01-31", "2011-03-31")
      expected = dates.select_rows(slicer)
      actual = dates.loc[slicer]
      assert_frame_equal(expected, actual, check_freq=False)
  
imports: import datetime
  import re
  import numpy
  import pandas
  import pytest
  from pandas.testing import assert_frame_equal
label_desc: Use image node_id 18 for calling a global function with example usage: test_slice_dates(dates) without return types