code: def test_fillna_columns_multiindex():
      columns = pd.MultiIndex.from_tuples([("a", "b"), ("d", "e")])
      pdf = pd.DataFrame(
          {"0": [1, 2, None, 3, None], "1": [None, None, None, None, 4]}
      )
      pdf.columns = columns
      gdf = cudf.from_pandas(pdf)
  
      expected = pdf.fillna(10)
      actual = gdf.fillna(10)
  
      assert_eq(expected, actual)
  
imports: import re
  from decimal import Decimal
  import numpy
  import pandas
  import pytest
  import cudf
  from cudf.core._compat import PANDAS_GE_134, PANDAS_GE_150
  from cudf.core.dtypes import Decimal32Dtype, Decimal64Dtype, Decimal128Dtype
  from cudf.testing._utils import INTEGER_TYPES, NUMERIC_TYPES, assert_eq, assert_exceptions_equal
label_desc: Use image node_id 33 for calling a global function with example usage: test_fillna_columns_multiindex() without return types