code: def test_frame_getitem_multicolumn_empty_level():
      df = DataFrame({"a": ["1", "2", "3"], "b": ["2", "3", "4"]})
      df.columns = [
          ["level1 item1", "level1 item2"],
          ["", "level2 item2"],
          ["level3 item1", "level3 item2"],
      ]
  
      result = df["level1 item1"]
      expected = DataFrame(
          [["1"], ["2"], ["3"]],
          index=df.index,
          columns=["level3 item1"],
      )
      tm.assert_frame_equal(result, expected)
  
imports: import numpy
  import pytest
  from pandas import DataFrame, Index, MultiIndex, Series
  import pandas._testing
  from pandas.core.indexing import IndexingError
label_desc: Use image node_id 10 for calling a global function with example usage: test_frame_getitem_multicolumn_empty_level() without return types