code: def dist_init(self):
      dist.init_process_group(
          backend=BACKEND,
          world_size=self.world_size,
          rank=self.rank,
          init_method=f"file://{self.file_name}",
      )
  
      # set device for nccl pg for collectives
      if BACKEND == "nccl":
          torch.cuda.set_device(self.rank)
  
imports: import os
  import sys
  from functools import wraps, partial
  import torch
  import torch.distributed
  from torch.testing._internal.common_distributed import MultiProcessTestCase, TEST_SKIPS
  from torch.testing._internal.common_utils import run_tests, TEST_WITH_DEV_DBG_ASAN
label_desc: Use image node_id 6 for calling the TestObjectCollectives obj's underlying member method code with example usage: obj.dist_init() without return types