docstr: Return an empty mapping object
docstr_tok: ["Return","an","empty","mapping","object"]
code: def _empty_mapping(self):
      """Return an empty mapping object"""
      return self.type2test()
  
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 2 for calling the WeakKeyDictionaryTestCase obj's underlying member method code with example usage: obj._empty_mapping() and returns: self