code: def c2_normal_to_sub_bn(key, model_keys):
      """
      Convert BN parameters to Sub-BN parameters if model contains Sub-BNs.
      Args:
          key (OrderedDict): source dict of parameters.
          mdoel_key (OrderedDict): target dict of parameters.
      Returns:
          new_sd (OrderedDict): converted dict of parameters.
      """
      if "bn.running_" in key:
          if key in model_keys:
              return key
  
          new_key = key.replace("bn.running_", "bn.split_bn.running_")
          if new_key in model_keys:
              return new_key
      else:
          return key
  
imports: import copy
  import math
  import numpy
  import os
  import pickle
  from collections import OrderedDict
  import torch
  import slowfast.utils.distributed
  import slowfast.utils.logging
  from slowfast.utils.c2_model_loading import get_name_convert_func
  from slowfast.utils.env import checkpoint_pathmgr
label_desc: Use image node_id 11 for calling a global function with example usage: c2_normal_to_sub_bn(key, model_keys) and returns: key, key, new_key