code: def test_completed_prefetch_yieldsRemainingIfIterationStops(
      self, rayWaitMock
  ):
      # Test for issue #7106
      # In versions of Ray up to 0.8.1, if the pre-fetch generator failed to
      # run to completion, then the TaskPool would fail to clear up already
      # fetched tasks resulting in stale object refs being returned
      pool = TaskPool()
      for i in range(10):
          task = createMockWorkerAndObjectRef(i)
          pool.add(*task)
  
      rayWaitMock.return_value = (list(range(10)), [])
  
      # This should fetch just the first item in the list
      try:
          for _ in pool.completed_prefetch():
              # Simulate a worker failure returned by ray.get()
              raise ray.exceptions.RayError
      except ray.exceptions.RayError:
          pass
  
      # This fetch should return the remaining pre-fetched tasks
      fetched = [pair[1] for pair in pool.completed_prefetch()]
      self.assertListEqual(fetched, list(range(1, 10)))
  
file_path: ray/python/ray/rllib/utils/tests/test_taskpool.py
imports: import unittest
  from unittest.mock import patch
  import ray
  from ray.rllib.utils.actors import TaskPool
label_desc: Use image node_id 4 for calling the TaskPoolTest obj's underlying member method code with example usage: obj.test_completed_prefetch_yieldsRemainingIfIterationStops(rayWaitMock) without return types