code: def __init__(self, evaluator: JoinableEvaluator):
      self.evaluator = evaluator
  
imports: import contextlib
  import functools
  import torch
  import torch.distributed
  from torch.distributed.algorithms.join import Join, Joinable, JoinHook
  import torch.nn
  from parlai.scripts.eval_model import Evaluator
  from parlai.scripts.train_model import TrainLoop
  from parlai.utils.distributed import is_distributed, get_dist_group
label_desc: Use image node_id 1 to create a new EvaluatorJoinHook object from inherited base classes: JoinHook with example: obj = EvaluatorJoinHook(evaluator)