code: def forward(self, x):
      residual = x
      y = self.layers(x)
      if self.shortcut:
          residual = self.shortcut(x)
      y += residual
      y = F.relu(y)
      return y
  
imports: import torch
  import torch.nn
  import torch.nn.functional
label_desc: Use image node_id 2 for calling the PerturbBasicBlock obj's underlying member method code with example usage: obj.forward(x) and returns: y