code: def _register_hook(self):
      layer = self._find_layer()
      assert layer is not None, f"hidden layer ({self.layer}) not found"
      handle = layer.register_forward_hook(self._hook)
      self.hook_registered = True
  
imports: import copy
  import random
  from functools import wraps, partial
  import torch
  from torch import nn, einsum
  import torch.nn.functional
  from torchvision import transforms
  from einops import rearrange, reduce, repeat
label_desc: Use image node_id 4 for calling the NetWrapper obj's underlying member method code with example usage: obj._register_hook() without return types