code: def test_dataframe_simple(func):
      df = cudf.DataFrame({"x": [1, 2, 3], "y": [4, 5, 6]})
      expected = func(df)
  
      a = DataFrame(example=df)
      L = func(a).stream.sink_to_list()
  
      a.emit(df)
  
      assert_eq(L[0], expected)
  
imports: import json
  import operator
  import numpy
  import pandas
  import pytest
  from dask.dataframe.utils import assert_eq
  from distributed import Client
  from streamz import Stream
  from streamz.dask import DaskStream
  from streamz.dataframe import Aggregation, DataFrame, DataFrames, Series
label_desc: Use image node_id 10 for calling a global function with example usage: test_dataframe_simple(func) without return types