code: def __init__(self, in_dim: int, out_dim: int):
      super(StemBlock, self).__init__()
  
      self.conv = layers.ConvBNReLU(in_dim, out_dim, 3, stride=2)
  
      self.left = nn.Sequential(
          layers.ConvBNReLU(out_dim, out_dim // 2, 1),
          layers.ConvBNReLU(out_dim // 2, out_dim, 3, stride=2),
      )
  
      self.right = nn.MaxPool2D(kernel_size=3, stride=2, padding=1)
  
      self.fuse = layers.ConvBNReLU(out_dim * 2, out_dim, 3)
  
imports: import os
  from typing import Union, List, Tuple
  import numpy
  import paddle
  import paddle.nn
  import paddle.nn.functional
  from paddlehub.module.module import moduleinfo
  import paddlehub.vision.segmentation_transforms
  from paddlehub.module.cv_module import ImageSegmentationModule
  import bisenet_cityscapes.layers
label_desc: Use image node_id 1 to create a new StemBlock object from inherited base classes: nn with example: obj = StemBlock(in_dim, out_dim)