code: def prepare_data():
      rs = np.random.RandomState(0)
      df = pd.DataFrame(
          {
              "a": rs.randint(10, size=100),
              "b": rs.rand(100),
              "c": rs.choice(list("abc"), size=100),
          }
      )
  
      with tempfile.TemporaryDirectory() as tempdir:
          yield tempdir, df
  
file_path: mars/mars/optimization/logical/tileable/tests/test_head.py
imports: import os
  import tempfile
  import pandas
  import numpy
  import pytest
  from .....None import dataframe
  from .....core import TileableGraph, TileableGraphBuilder, enter_mode
  from .....dataframe.indexing.iloc import DataFrameIlocGetItem, SeriesIlocGetItem
  from ..None import optimize
label_desc: Use image node_id 1 for calling a global function with example usage: prepare_data() without return types