code: def get_master_addr(
      prior=None, launcher: str = None
  ) -> Optional[str]:
      if prior is None:
          if launcher == "slurm":
              if not is_in_slurm_step():
                  raise RuntimeError(
                      "This process seems not to be launched by 'srun'"
                  )
  
              # e.g nodelist = foo[1-10],bar[3-8] or foo4,bar[2-10]
              nodelist = os.environ["SLURM_STEP_NODELIST"]
              prior = (
                  nodelist.split(",")[0].split("-")[0].replace("[", "")
              )
  
      if prior is not None:
          return str(prior)
      else:
          return os.environ.get("MASTER_ADDR")
  
imports: import dataclasses
  import os
  import socket
  from typing import Optional
  import torch
  import torch.distributed
label_desc: Use image node_id 9 for calling a global function with example usage: get_master_addr(prior, launcher) and returns: str, os