code: def test_ensure_exists(self):
      ARG = 0
      for func, out in [
          (
              self.handler._handle_event_deletion,
              f"Found Event with id: {ARG}, but no matching event "
              "creation in the trace. Backfilling the trace now. "
              "Perhaps the sanitizer was enabled after some torch operations?",
          ),
          (
              self.handler._handle_memory_deallocation,
              f"Found tensor with pointer: {ARG}, but no matching tensor "
              "allocation in the trace. Backfilling the trace now. "
              "Perhaps the sanitizer was enabled after some torch operations?",
          ),
      ]:
          with self.subTest(func=func, out=out):
              with self.assertLogs() as captured:
                  func(ARG)
              self.assertEqual(captured.records[0].getMessage(), out)
  
imports: import sys
  import textwrap
  import traceback
  from typing import List
  import torch
  import torch.cuda._sanitizer
  from torch.cuda._sanitizer import StreamId, DataPtr, EventId
  from torch.testing._internal.common_utils import TestCase, run_tests, NoTest, TEST_CUDA
label_desc: Use image node_id 2 for calling the TestMessages obj's underlying member method code with example usage: obj.test_ensure_exists() without return types