code: def forward(self, img):
      batch, device = img.shape[0], img.device
  
      x = self.to_patch_embedding(img)
      x += self.pos_embedding.to(device, dtype=x.dtype)
  
      r = repeat(self.register_tokens, "n d -> b n d", b=batch)
  
      x, ps = pack([x, r], "b * d")
  
      x = self.transformer(x)
  
      x, _ = unpack(x, ps, "b * d")
  
      x = x.mean(dim=1)
  
      x = self.to_latent(x)
      return self.linear_head(x)
  
imports: import torch
  from torch import nn
  from einops import rearrange, repeat, pack, unpack
  from einops.layers.torch import Rearrange
label_desc: Use image node_id 2 for calling the SimpleViT obj's underlying member method code with example usage: obj.forward(img) and returns: self