code: def test_at_frame_multiple_columns(self):
      # GH#48296 - at shouldn't modify multiple columns
      df = DataFrame({"a": [1, 2], "b": [3, 4]})
      new_row = [6, 7]
      with pytest.raises(
          InvalidIndexError,
          match=f"You can only assign a scalar value not a \\{type(new_row)}",
      ):
          df.at[5] = new_row
  
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 5 for calling the TestAtErrors obj's underlying member method code with example usage: obj.test_at_frame_multiple_columns() without return types