code: def forward(self, x):
      x1 = self.inc(x)
      x2 = self.down1(x1)
      x3 = self.down2(x2)
      x4 = self.down3(x3)
      x5 = self.down4(x4)
      x = self.up1(x5, x4)
      x = self.up2(x, x3)
      x = self.up3(x, x2)
      x = self.up4(x, x1)
      logits = self.outc(x)
      return logits
  
imports: import torch
  import torch.nn
  import torch.nn.functional
label_desc: Use image node_id 2 for calling the UNet obj's underlying member method code with example usage: obj.forward(x) and returns: logits