code: def __init__(self, dim, fn, sandwich=False):
      super().__init__()
      self.norm = nn.LayerNorm(dim)
      self.norm_out = nn.LayerNorm(dim) if sandwich else nn.Identity()
      self.fn = fn
  
imports: import torch
  import torch.nn.functional
  from einops import rearrange
  from torch import nn
label_desc: Use image node_id 1 to create a new PreNorm object from inherited base classes: nn with example: obj = PreNorm(dim, fn, sandwich)