code: def forward(self, x):
      x = torch.cat(x, dim=1) if isinstance(x, tuple) else x
      return self.act(self.bn(x))
  
imports: import os
  import torch
  import torch.nn
  import torch.nn.functional
  import torch.utils.model_zoo
  from collections import OrderedDict
  from .adaptive_avgmax_pool import adaptive_avgmax_pool2d
  from .convert_from_mxnet import convert_from_mxnet, has_mxnet
label_desc: Use image node_id 2 for calling the CatBnAct obj's underlying member method code with example usage: obj.forward(x) and returns: self