code: def test_unsorted_dates_slice(dates):
      """Raise Error if the dates are unsorted."""
      with pytest.raises(
          ValueError,
          match="The DatetimeIndex should be monotonic increasing.",
      ):
          dates.iloc[::-1].select_rows(
              slice("2011-01-31", "2011-03-31")
          )
  
imports: import datetime
  import re
  import numpy
  import pandas
  import pytest
  from pandas.testing import assert_frame_equal
label_desc: Use image node_id 13 for calling a global function with example usage: test_unsorted_dates_slice(dates) without return types