code: def forward(self, x):
      x = self.conv(x)
      left = self.left(x)
      right = self.right(x)
      concat = paddle.concat([left, right], axis=1)
      return self.fuse(concat)
  
imports: import os
  import paddle
  import paddle.nn
  import paddle.nn.functional
  from paddleseg import utils
  from paddleseg.cvlibs import manager, param_init
  from paddleseg.models import layers
label_desc: Use image node_id 2 for calling the StemBlock obj's underlying member method code with example usage: obj.forward(x) and returns: self