code: def forward(self, img_in):
      out_1 = self.l1(img_in)
      out_2 = self.R(out_1)
      out_3 = out_1 + self.l2(out_2)
      out_4 = self.px(out_3)
      return self.conv_final(out_4)
  
imports: import torch
  from torch import nn
  from torchvision.models import vgg19
  from torch.autograd import Variable
label_desc: Use image node_id 2 for calling the Generator obj's underlying member method code with example usage: obj.forward(img_in) and returns: self