code: def forward(self, x: Tensor) -> Tensor:
      for block in self.children():
          x = block(x)
      return x
  
imports: from typing import Optional
  import numpy
  import torch
  import torch.nn
  from torch import Tensor
label_desc: Use image node_id 2 for calling the RegStage obj's underlying member method code with example usage: obj.forward(x) and returns: x