code: def get_stage_num(self) -> int:
      return self._stage_num
  
imports: import threading
  from typing import List
  import torch.distributed
  from torch.distributed import rpc
  from colossalai.legacy.tensor import ProcessGroup
label_desc: Use image node_id 12 for calling the PipelineProcessGroup obj's underlying member method code with example usage: obj.get_stage_num() and returns: self