code: def forward(self, x: paddle.Tensor) -> paddle.Tensor:
      out_list = []
      out1 = self.conv_list[0](x)
      for idx, conv in enumerate(self.conv_list[1:]):
          if idx == 0:
              if self.stride == 2:
                  out = conv(self.avd_layer(out1))
              else:
                  out = conv(out1)
          else:
              out = conv(out)
          out_list.append(out)
  
      if self.stride == 2:
          out1 = self.skip(out1)
      out_list.insert(0, out1)
      out = paddle.concat(out_list, axis=1)
      return out
  
imports: from typing import Union, List, Tuple
  import math
  import paddle
  import paddle.nn
  import stdc1_seg_cityscapes.layers
label_desc: Use image node_id 2 for calling the CatBottleneck obj's underlying member method code with example usage: obj.forward(x) and returns: out