code: def is_first_stage(self):
      return (self.pp_rank % self.actual_stage_num) == 0
  
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 5 for calling the ChimeraWorker obj's underlying member method code with example usage: obj.is_first_stage() and returns: unknown