code: def test_roundtrip_none_rangeindex(tmpdir):
      fn = str(tmpdir.join("test.parquet"))
      gdf = cudf.DataFrame(
          {"id": [0, 1, 2, 3], "val": [None, None, 0, 1]},
          index=pd.RangeIndex(start=5, stop=9),
      )
      dask_cudf.from_cudf(gdf, npartitions=2).to_parquet(fn)
      ddf2 = dask_cudf.read_parquet(fn)
      dd.assert_eq(gdf, ddf2, check_index=True)
  
imports: import glob
  import math
  import os
  import numpy
  import pandas
  import pytest
  import dask
  from dask import dataframe
  from dask.utils import natural_sort_key
  import cudf
  import dask_cudf
label_desc: Use image node_id 6 for calling a global function with example usage: test_roundtrip_none_rangeindex(tmpdir) without return types