code: def forward(self, x, attn_mask=None, memories=None):
      for ind, (attn, ff) in enumerate(self.layers):
          layer_memories = memories[ind] if exists(memories) else None
  
          x = attn(x, attn_mask=attn_mask, memories=layer_memories) + x
          x = ff(x) + x
      return x
  
imports: import torch
  from torch import nn
  import torch.nn.functional
  from einops import rearrange, repeat
  from einops.layers.torch import Rearrange
label_desc: Use image node_id 2 for calling the Transformer obj's underlying member method code with example usage: obj.forward(x, attn_mask, memories) and returns: x