code: def test_offset(self, case):
      offset, cases = case
      for base, expected in cases.items():
          assert_offset_equal(offset, base, expected)
  
imports: from __future__ import annotations
  from datetime import datetime
  import pytest
  from pandas._libs.tslibs import Timestamp
  from pandas._libs.tslibs.offsets import MonthBegin, MonthEnd, SemiMonthBegin, SemiMonthEnd
  from pandas import DatetimeIndex, Series, _testing
  from pandas.tests.tseries.offsets.common import assert_is_on_offset, assert_offset_equal
label_desc: Use image node_id 2 for calling the TestSemiMonthEnd obj's underlying member method code with example usage: obj.test_offset(case) without return types