code: def forward(self, x):
      return self.ln(x)
  
imports: import torch
  import torch.nn
  import torch.nn.functional
  from torch import Tensor
  from torch.nn import LayerNorm
  import logging
  import warnings
  from typing import Tuple, Optional
  from ..losses.pytorch import MAE
  from ..common._base_windows import BaseWindows
label_desc: Use image node_id 2 for calling the MaybeLayerNorm obj's underlying member method code with example usage: obj.forward(x) and returns: self