code: def forward(self, img):
      device, dtype = img.device, img.dtype
  
      x = self.to_patch_embedding(img)
      freqs = torch.view_as_real(fft2(img))
  
      f = self.to_freq_embedding(freqs)
  
      x += self.pos_embedding.to(device, dtype=dtype)
      f += self.freq_pos_embedding.to(device, dtype=dtype)
  
      x, ps = pack((f, x), "b * d")
  
      x = self.transformer(x)
  
      _, x = unpack(x, ps, "b * d")
      x = reduce(x, "b n d -> b d", "mean")
  
      x = self.to_latent(x)
      return self.linear_head(x)
  
imports: import torch
  from torch.fft import fft2
  from torch import nn
  from einops import rearrange, reduce, 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