code: def test_at_frame_raises_key_error2(self, indexer_al):
      # GH#31724 .at should match .loc
      df = DataFrame({"A": [1, 2, 3]}, index=list("abc"))
      result = indexer_al(df)["a", "A"]
      assert result == 1
  
      with pytest.raises(KeyError, match="^0$"):
          indexer_al(df)["a", 0]
  
imports: from datetime import datetime, timezone
  import numpy
  import pytest
  from pandas.errors import InvalidIndexError
  from pandas import CategoricalDtype, CategoricalIndex, DataFrame, DatetimeIndex, Index, MultiIndex, Series, Timestamp
  import pandas._testing
label_desc: Use image node_id 4 for calling the TestAtErrors obj's underlying member method code with example usage: obj.test_at_frame_raises_key_error2(indexer_al) without return types