code: def test_groupby_corner(self):
      midx = MultiIndex(
          levels=[["foo"], ["bar"], ["baz"]],
          codes=[[0], [0], [0]],
          names=["one", "two", "three"],
      )
      df = DataFrame(
          [np.random.default_rng(2).random(4)],
          columns=["a", "b", "c", "d"],
          index=midx,
      )
      # should work
      df.groupby(level="three")
  
imports: import datetime
  import numpy
  import pytest
  import pandas
  from pandas import DataFrame, MultiIndex, Series
  import pandas._testing
label_desc: Use image node_id 5 for calling the TestMultiLevel obj's underlying member method code with example usage: obj.test_groupby_corner() without return types