code: def forward(self, x):
      h = self.normalize(x)
      return self.run(h)
  
imports: import torch
  import torch.nn
  from torch.autograd import Variable
  from torch.nn import functional
  import torchvision
  from torchvision import models
  import pytorch_lightning
label_desc: Use image node_id 4 for calling the PerceptualVGG19 obj's underlying member method code with example usage: obj.forward(x) and returns: self