docstr: Freeze BatchNorm layers.
code: def freeze_bn(self):
      """Freeze BatchNorm layers."""
      for layer in self.modules():
          if isinstance(layer, nn.BatchNorm2d):
              layer.eval()
  
imports: from torch import nn
  from torch.nn import functional
  import torch
  from torchvision import models
  from torchvision.models import resnet34, resnet101, resnet50, resnet152
  import torchvision
label_desc: Use image node_id 3 for calling the UNetResNetV4 obj's underlying member method code with example usage: obj.freeze_bn() without return types