code: def forward(self, x1, x2):
      x1 = self.up(x1)
      diffY = x2.size()[2] - x1.size()[2]
      diffX = x2.size()[3] - x1.size()[3]
      x1 = F.pad(
          x1,
          (
              diffX // 2,
              diffX - diffX // 2,
              diffY // 2,
              diffY - diffY // 2,
          ),
      )
      x = torch.cat([x2, x1], dim=1)
      x = self.conv(x)
      return x
  
imports: import torch.nn
  import torch.nn.functional
  import torch
label_desc: Use image node_id 2 for calling the UpLayer obj's underlying member method code with example usage: obj.forward(x1, x2) and returns: x