code: def freeze_bn(self):
      for module in self.modules():
          if isinstance(module, nn.BatchNorm2d):
              module.eval()
  
imports: import torch
  import logging
  import torch.nn
  import torch.nn.functional
  from torchvision import models
  from itertools import chain
  import numpy
  from collections import OrderedDict
label_desc: Use image node_id 5 for calling the UperNet obj's underlying member method code with example usage: obj.freeze_bn() without return types