code: def testDiscard(self):
      a = object()
      b = object()
      set1 = object_identity.ObjectIdentitySet([a, b])
      set1.discard(a)
      self.assertIn(b, set1)
      self.assertNotIn(a, set1)
  
file_path: tensorflow/tensorflow/python/util/object_identity_test.py
imports: from tensorflow.python.platform import test
  from tensorflow.python.util import nest
  from tensorflow.python.util import object_identity
label_desc: Use image node_id 2 for calling the ObjectIdentitySetTest obj's underlying member method code with example usage: obj.testDiscard() without return types