code: def test_1_csv_data(self):
      GetData().download_data(
          file_name="csv_data_cn.zip", target_dir=SOURCE_DIR
      )
      stock_name = set(
          map(lambda x: x.name[:-4].upper(), SOURCE_DIR.glob("*.csv"))
      )
      self.assertEqual(len(stock_name), 85, "get csv data failed")
  
file_path: qlib/tests/test_get_data.py
imports: import shutil
  import unittest
  from pathlib import Path
  import qlib
  from qlib.data import D
  from qlib.tests.data import GetData
label_desc: Use image node_id 4 for calling the TestGetData obj's underlying member method code with example usage: obj.test_1_csv_data() without return types