class_docstr: FP16 Optimizer without weight fusion to support LAMB optimizer
  
  For usage example please see, TODO:  DeepSpeed V2 Tutorial
code: def _get_param_groups(self):
      return self.optimizer.param_groups
  
imports: from deepspeed.moe.utils import split_params_grads_into_shared_and_expert_params
  import torch
  from torch._utils import _flatten_dense_tensors
  from deepspeed.runtime import DeepSpeedOptimizer
  from deepspeed.runtime.utils import get_global_norm, CheckOverflow, get_weight_norm
  from deepspeed.runtime.fp16.loss_scaler import INITIAL_LOSS_SCALE, SCALE_WINDOW, MIN_LOSS_SCALE
  from deepspeed.utils import logger
  from deepspeed.checkpoint.constants import OPTIMIZER_STATE_DICT
  from deepspeed import comm
label_desc: Use image node_id 13 for calling the FP16_UnfusedOptimizer obj's underlying member method code with example usage: obj._get_param_groups() and returns: self