code: def test_isub(self):
      self.s -= set(self.items2)
      for c in self.items + self.items2:
          if c in self.items and c not in self.items2:
              self.assertIn(c, self.s)
          else:
              self.assertNotIn(c, self.s)
  
imports: import unittest
  from weakref import WeakSet
  import copy
  import string
  from collections import UserString
  from collections.abc import Set, MutableSet
  import gc
  import contextlib
  from test import support
label_desc: Use image node_id 35 for calling the TestWeakSet obj's underlying member method code with example usage: obj.test_isub() without return types