code: def forward(self, x: paddle.Tensor) -> Tuple:
      short_cuts = []
      x = self.double_conv(x)
      for down_sample in self.down_sample_list:
          short_cuts.append(x)
          x = down_sample(x)
      return x, short_cuts
  
imports: import os
  from typing import Union, List, Tuple
  import paddle
  from paddle import nn
  import paddle.nn.functional
  import numpy
  from paddlehub.module.module import moduleinfo
  import paddlehub.vision.segmentation_transforms
  from paddlehub.module.cv_module import ImageSegmentationModule
  import unet_cityscapes.layers
label_desc: Use image node_id 3 for calling the Encoder obj's underlying member method code with example usage: obj.forward(x) and returns: x,  short_cuts