code: def test_keys(self):
      d = self._empty_mapping()
      self.assertEqual(list(d.keys()), [])
      d = self.reference
      self.assertIn(next(iter(self.inmapping.keys())), d.keys())
      self.assertNotIn(next(iter(self.other.keys())), d.keys())
      self.assertRaises(TypeError, d.keys, None)
  
imports: import copy
  import gc
  import random
  import threading
  import unittest
  import torch
  from torch.testing._internal.common_utils import find_library_location, IS_FBCODE, IS_MACOS, IS_SANDCASTLE, IS_WINDOWS, run_tests, TestCase
  from torch.utils.weak import _WeakHashRef, WeakIdKeyDictionary
label_desc: Use image node_id 10 for calling the WeakKeyDictionaryScriptObjectTestCase obj's underlying member method code with example usage: obj.test_keys() without return types