code: def __init__(self, key_field):
      self.blocks = None
      self.key_field = key_field
      self.num_accesses = 0
      self.total_time = 0
  
imports: import bisect
  import logging
  import random
  import time
  from collections import defaultdict
  from typing import TYPE_CHECKING, Any, List, Optional
  import numpy
  import ray
  from ray.data._internal.remote_fn import cached_remote_fn
  from ray.data.block import BlockAccessor
  from ray.data.context import DataContext
  from ray.types import ObjectRef
  from ray.util.annotations import PublicAPI
label_desc: Use image node_id 1 to create a new _RandomAccessWorker object  with example: obj = _RandomAccessWorker(key_field)