code: def pg_worker(rank, world_size, init_file, func, *args):
      dist.init_process_group(
          dist.Backend.NCCL,
          init_method="file://" + init_file,
          rank=rank,
          world_size=world_size,
      )
      func(*args)
      dist.destroy_process_group()
  
imports: import functools
  import tempfile
  import pytest
  import torch
  import torch.distributed
  import torch.multiprocessing
  import torch.nn
  from torch.nn.parallel import DistributedDataParallel
  from fairscale.experimental.nn import SyncBatchNorm
  from fairscale.nn.checkpoint import checkpoint_wrapper
label_desc: Use image node_id 1 for calling a global function with example usage: pg_worker(rank, world_size, init_file, func) without return types