code: def add_param_group(self, param_group):
      super().add_param_group(param_group)
      for name, default in self.defaults.items():
          if isinstance(default, torch.Tensor):
              self.param_groups[len(self.param_groups) - 1][
                  name
              ] = default.clone()
  
file_path: apex/apex/optimizers/fused_mixed_precision_lamb.py
imports: import torch
  from copy import deepcopy
  from itertools import chain
  from collections import defaultdict, abc
  from apex.multi_tensor_apply import multi_tensor_applier
label_desc: Use image node_id 4 for calling the FusedMixedPrecisionLamb obj's underlying member method code with example usage: obj.add_param_group(param_group) without return types