code: def bn_function(self, inputs: List[Tensor]) -> Tensor:
      concat_features = torch.cat(inputs, 1)
      bottleneck_output = self.conv1(
          self.relu1(self.norm1(concat_features))
      )
      return bottleneck_output
  
imports: import re
  from typing import Any, List, Tuple
  from collections import OrderedDict
  import torch
  import torch.nn
  import torch.nn.functional
  import torch.utils.checkpoint
  from torch import Tensor
label_desc: Use image node_id 2 for calling the _DenseLayer obj's underlying member method code with example usage: obj.bn_function(inputs) and returns: bottleneck_output