class_docstr: Test download tools
code: def tearDown(self):
      if os.path.exists(self.target_file):
          os.remove(self.target_file)
  
file_path: towhee/tests/unittests/models/utils/test_download.py
imports: import unittest
  import os
  from towhee.models.utils.download import download_from_url, checksum
label_desc: Use image node_id 5 for calling the TestDownload obj's underlying member method code with example usage: obj.tearDown() without return types