code: def __init__(self, bucket_size_mb: int = 25):
      self.bucket_size_mb = bucket_size_mb
      self.buckets: Dict[
          Tuple[torch.dtype, torch.device, ProcessGroup], Bucket
      ] = {}
  
file_path: ColossalAI/colossalai/legacy/nn/parallel/reducer.py
imports: import functools
  from typing import Callable, Dict, List, Optional, Tuple
  import torch
  import torch.distributed
  from torch import Tensor
  from torch.distributed import ProcessGroup
label_desc: Use image node_id 1 to create a new Reducer object  with example: obj = Reducer(bucket_size_mb)