code: def _check_bn(model):
      flag = [False]
      model.apply(lambda module: _check_bn_apply(module, flag))
      return flag[0]
  
imports: import warnings
  from collections import defaultdict
  from typing import Optional, Union
  import torch
  from pytext.config.component import create_optimizer
  from pytext.optimizer.lamb import Lamb
  from pytext.optimizer.madgrad import MADGRAD
  from pytext.optimizer.optimizers import Adagrad, Adam, AdamW, Optimizer, SGD
  from pytext.optimizer.radam import RAdam
  from torch.optim import Optimizer
label_desc: Use image node_id 2 for calling a global function with example usage: _check_bn(model) and returns: flag