code: def test_last_subset(self, frame_or_series):
      ts = DataFrame(
          np.random.default_rng(2).standard_normal((100, 4)),
          columns=Index(list("ABCD"), dtype=object),
          index=date_range("2000-01-01", periods=100, freq="12h"),
      )
      ts = tm.get_obj(ts, frame_or_series)
      with tm.assert_produces_warning(
          FutureWarning, match=last_deprecated_msg
      ):
          result = ts.last("10d")
      assert len(result) == 20
  
      ts = DataFrame(
          np.random.default_rng(2).standard_normal((30, 4)),
          columns=Index(list("ABCD"), dtype=object),
          index=date_range("2000-01-01", periods=30, freq="D"),
      )
      ts = tm.get_obj(ts, frame_or_series)
      with tm.assert_produces_warning(
          FutureWarning, match=last_deprecated_msg
      ):
          result = ts.last("10d")
      assert len(result) == 10
  
      with tm.assert_produces_warning(
          FutureWarning, match=last_deprecated_msg
      ):
          result = ts.last("21D")
      expected = ts["2000-01-10":]
      tm.assert_equal(result, expected)
  
      with tm.assert_produces_warning(
          FutureWarning, match=last_deprecated_msg
      ):
          result = ts.last("21D")
      expected = ts[-21:]
      tm.assert_equal(result, expected)
  
      with tm.assert_produces_warning(
          FutureWarning, match=last_deprecated_msg
      ):
          result = ts[:0].last("3ME")
      tm.assert_equal(result, ts[:0])
  
file_path: pandas/pandas/tests/frame/methods/test_first_and_last.py
imports: import numpy
  import pytest
  import pandas
  from pandas import DataFrame, Index, bdate_range, date_range
  import pandas._testing
label_desc: Use image node_id 3 for calling the TestFirst obj's underlying member method code with example usage: obj.test_last_subset(frame_or_series) without return types