docstr: Validate the output shape of Tacotron2Loss.
docstr_tok: ["Validate","the","output","shape","of","Tacotron2Loss","."]
code: def test_tacotron2_loss_shape(self):
      """Validate the output shape of Tacotron2Loss."""
      n_batch = 16
  
      (
          mel_specgram,
          mel_specgram_postnet,
          gate_out,
          truth_mel_specgram,
          truth_gate_out,
      ) = self._get_inputs(n_batch=n_batch)
  
      mel_loss, mel_postnet_loss, gate_loss = Tacotron2Loss()(
          (mel_specgram, mel_specgram_postnet, gate_out),
          (truth_mel_specgram, truth_gate_out),
      )
  
      self.assertEqual(mel_loss.size(), torch.Size([]))
      self.assertEqual(mel_postnet_loss.size(), torch.Size([]))
      self.assertEqual(gate_loss.size(), torch.Size([]))
  
file_path: audio/test/torchaudio_unittest/example/tacotron2/tacotron2_loss_impl.py
imports: import torch
  from pipeline_tacotron2.loss import Tacotron2Loss
  from torch.autograd import gradcheck, gradgradcheck
  from torchaudio_unittest.common_utils import TestBaseMixin, torch_script
label_desc: Use image node_id 1 for calling the Tacotron2LossShapeTests obj's underlying member method code with example usage: obj.test_tacotron2_loss_shape() without return types