code: def __init__(
      self, name, in_channels, mid_channels, out_channels, use_bias
  ):
      super(MiddleNet, self).__init__()
      self._sn_conv1 = SNConv(
          name=name + "_sn_conv1",
          in_channels=in_channels,
          out_channels=mid_channels,
          kernel_size=1,
          use_bias=use_bias,
          norm_layer=None,
          act=None,
      )
      self._pad2d = nn.Pad2D(padding=[1, 1, 1, 1], mode="replicate")
      self._sn_conv2 = SNConv(
          name=name + "_sn_conv2",
          in_channels=mid_channels,
          out_channels=mid_channels,
          kernel_size=3,
          use_bias=use_bias,
      )
      self._sn_conv3 = SNConv(
          name=name + "_sn_conv3",
          in_channels=mid_channels,
          out_channels=out_channels,
          kernel_size=1,
          use_bias=use_bias,
      )
  
imports: import paddle
  import paddle.nn
  from arch.spectral_norm import spectral_norm
label_desc: Use image node_id 1 to create a new MiddleNet object from inherited base classes: nn with example: obj = MiddleNet(name, in_channels, mid_channels, out_channels, use_bias)