code: def forward(self, x):
      return (x - self.mean) / (self.std + self.eps)
  
file_path: captum/captum/_utils/models/linear_model/train.py
imports: import time
  import warnings
  from typing import Any, Callable, Dict, List, Optional
  import torch
  import torch.nn
  from captum._utils.models.linear_model.model import LinearModel
  from torch.utils.data import DataLoader
label_desc: Use image node_id 2 for calling the NormLayer obj's underlying member method code with example usage: obj.forward(x) and returns: unknown