code: def test_unpartitioned_dataframe(setup_cluster):
      from dask import dataframe as dd
      from pandas._testing import assert_frame_equal
      import pandas as pd
      from sklearn.datasets import load_iris
  
      boston = load_iris()
      pd.DataFrame(boston.data, columns=boston["feature_names"]).to_csv(
          "./boston_housing_data.csv"
      )
  
      df = dd.read_csv(r"./boston_housing_data.csv")
      df["sepal length (cm)"] = df["sepal length (cm)"] / 2
  
      dask_res = df.compute()
      assert_frame_equal(dask_res, df.compute(scheduler=mars_scheduler))
      assert_frame_equal(
          dask_res, convert_dask_collection(df).execute().fetch()
      )
  
file_path: mars/mars/contrib/dask/tests/test_dask.py
imports: import pytest
  from ....utils import lazy_import
  from ..None import convert_dask_collection, mars_scheduler
label_desc: Use image node_id 3 for calling a global function with example usage: test_unpartitioned_dataframe(setup_cluster) without return types