code: def test_getitem(test_frame):
      g = test_frame.groupby("A")
  
      expected = g.B.apply(lambda x: x.resample("2s").mean())
  
      result = g.resample("2s").B.mean()
      tm.assert_series_equal(result, expected)
  
      result = g.B.resample("2s").mean()
      tm.assert_series_equal(result, expected)
  
      msg = "DataFrameGroupBy.resample operated on the grouping columns"
      with tm.assert_produces_warning(FutureWarning, match=msg):
          result = g.resample("2s").mean().B
      tm.assert_series_equal(result, expected)
  
imports: from textwrap import dedent
  import numpy
  import pytest
  from pandas.compat import is_platform_windows
  import pandas
  from pandas import DataFrame, Index, Series, TimedeltaIndex, Timestamp
  import pandas._testing
  from pandas.core.indexes.datetimes import date_range
label_desc: Use image node_id 4 for calling a global function with example usage: test_getitem(test_frame) without return types