code: def gen_data3():
      arrays = [
          ["Falcon", "Falcon", "Parrot", "Parrot"],
          ["Captive", "Wild", "Captive", "Wild"],
      ]
      index = pd.MultiIndex.from_arrays(
          arrays, names=("Animal", "Type")
      )
      df = pd.DataFrame(
          {"Max Speed": [390.0, 350.0, 30.0, 20.0]}, index=index
      )
      yield df
  
file_path: mars/mars/dataframe/groupby/tests/test_groupby_nunique_execution.py
imports: import numpy
  import pandas
  import pytest
  from ....None import dataframe
label_desc: Use image node_id 3 for calling a global function with example usage: gen_data3() without return types