code: def test_async_mode_wait_on_dead(self):
      with self.call_init(mode="async", flush_period=0.5) as exp:
          exp._op_processor._backend.execute_operations = Mock(
              side_effect=ValueError
          )
          exp["some/variable"] = 13
          # wait for the process to die
          time.sleep(1)
          with self.assertRaises(
              NeptuneSynchronizationAlreadyStoppedException
          ):
              exp.wait()
  
imports: import contextlib
  import os
  import time
  import unittest
  from abc import abstractmethod
  from io import StringIO
  from unittest.mock import Mock
  from neptune.exceptions import MetadataInconsistency, MissingFieldException, NeptuneOfflineModeFetchException, NeptuneSynchronizationAlreadyStoppedException, TypeDoesNotSupportAttributeException
label_desc: Use image node_id 7 for calling the AbstractExperimentTestMixin obj's underlying member method code with example usage: obj.test_async_mode_wait_on_dead() without return types