code: def forward(self, src, tgt, src_mask, tgt_mask):
      encoder_outputs = self.encoder(src, src_mask)
      decoder_outputs = self.decoder(
          tgt, tgt_mask, encoder_outputs, src_mask
      )
  
      return self.output_dense(decoder_outputs)
  
imports: import torch
  import torch.nn
  import torch.nn.functional
  import math
  import copy
label_desc: Use image node_id 2 for calling the TransformerForSeq2Seq obj's underlying member method code with example usage: obj.forward(src, tgt, src_mask, tgt_mask) and returns: self