class_docstr: Block prefetcher using a local actor.
class_docstr_tok: ["Block","prefetcher","using","a","local","actor","."]
code: def __init__(self):
      self.prefetch_actor = self._get_or_create_actor_prefetcher()
  
imports: import logging
  import threading
  from contextlib import nullcontext
  from typing import Any, Callable, Iterator, List, Optional, Tuple
  import ray
  from ray.actor import ActorHandle
  from ray.data._internal.batcher import Batcher, ShufflingBatcher
  from ray.data._internal.block_batching.interfaces import Batch, BlockPrefetcher, CollatedBatch
  from ray.data._internal.stats import DatasetStats
  from ray.data.block import Block, BlockAccessor, DataBatch
  from ray.types import ObjectRef
  from ray.util.scheduling_strategies import NodeAffinitySchedulingStrategy
label_desc: Use image node_id 1 to create a new ActorBlockPrefetcher object from inherited base classes: BlockPrefetcher with example: obj = ActorBlockPrefetcher()