code: def forward(self, x, x_lengths, y, y_lengths):
      self.att1(y, x, x, None)
      _, a2 = self.att2(x, x_lengths, y, None)
      self.desired["att1"].append(self.att1.attn.squeeze(0))
      self.desired["att2"].append(a2)
  
imports: from collections import defaultdict
  import numpy
  import pytest
  import torch
  from espnet2.asr.decoder.rnn_decoder import RNNDecoder
  from espnet2.main_funcs.calculate_all_attentions import calculate_all_attentions
  from espnet2.train.abs_espnet_model import AbsESPnetModel
  from espnet.nets.pytorch_backend.rnn.attentions import AttAdd
  from espnet.nets.pytorch_backend.transformer.attention import MultiHeadedAttention
label_desc: Use image node_id 2 for calling the Dummy obj's underlying member method code with example usage: obj.forward(x, x_lengths, y, y_lengths) without return types