code: def _create_pp_rank_to_rpc_worker_id(self) -> None:
      stage_num = self.stage_num
      self.pp_rank_to_rpc_worker_id = [0] * (stage_num * 2)
      for pp_rank in range(stage_num):
          self.pp_rank_to_rpc_worker_id[pp_rank] = pp_rank
          self.pp_rank_to_rpc_worker_id[pp_rank + stage_num] = (
              stage_num - pp_rank - 1
          )
  
imports: import threading
  from typing import Callable, Dict, List
  import torch
  from torch._C._distributed_rpc import PyRRef
  from torch.futures import Future
  from colossalai.legacy.pipeline.pipeline_process_group import ppg
  from colossalai.legacy.pipeline.rpc._pipeline_base import Phase, PipelineEngineBase, UniqueKey, WorkerBase, WorkItem
label_desc: Use image node_id 3 for calling the ChimeraPipelineEngine obj's underlying member method code with example usage: obj._create_pp_rank_to_rpc_worker_id() without return types