code: def forward(self, input):
      # input = (input - self.mean) / self.std
      output = self.features(input)
      return output
  
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 VGGFeatures obj's underlying member method code with example usage: obj.forward(input) and returns: output