code: def tearDown(self):
      if os.path.exists(os_helper.TESTFN):
          os.unlink(os_helper.TESTFN)
  
imports: import unittest
  import base64
  import binascii
  import os
  from array import array
  from test.support import os_helper
  from test.support import script_helper
label_desc: Use image node_id 1 for calling the TestMain obj's underlying member method code with example usage: obj.tearDown() without return types