code: def test_groupby_drop_nan_with_multi_index():
      # GH 39895
      df = pd.DataFrame([[np.nan, 0, 1]], columns=["a", "b", "c"])
      df = df.set_index(["a", "b"])
      result = df.groupby(["a", "b"], dropna=False).first()
      expected = df
      tm.assert_frame_equal(result, expected)
  
imports: import numpy
  import pytest
  from pandas.compat.pyarrow import pa_version_under10p1
  from pandas.core.dtypes.missing import na_value_for_dtype
  import pandas
  import pandas._testing
  from pandas.tests.groupby import get_groupby_method_args
label_desc: Use image node_id 13 for calling a global function with example usage: test_groupby_drop_nan_with_multi_index() without return types