code: def norm2d(w_in):
      """Helper for building a norm2d layer."""
      return nn.BatchNorm2d(
          num_features=w_in, eps=cfg.BN.EPS, momentum=cfg.BN.MOM
      )
  
imports: import numpy
  import torch
  import torch.nn
  from pycls.core.config import cfg
  from torch.nn import Module
label_desc: Use image node_id 3 for calling a global function with example usage: norm2d(w_in) and returns: nn