docstr: Check that method `forward` produces correctly-shaped outputs.
docstr_tok: ["Check","that","method","`","forward","`","produces","correctly-shaped","outputs","."]
code: def test_output_shape_forward(self):
      r"""Check that method `forward` produces correctly-shaped outputs."""
      input_config = self._get_input_config()
      model_config = self._get_model_config()
  
      batch_size = input_config["batch_size"]
      time_length = input_config["time_length"]
  
      inputs = self._get_inputs()
      model = self._get_model()
  
      total_upsample_rate = math.prod(model_config["upsample_rates"])
  
      for _ in range(2):
          out = model(inputs)
          self.assertEqual(
              (batch_size, 1, total_upsample_rate * time_length),
              out.shape,
          )
  
imports: import math
  import torch
  from parameterized import parameterized
  from torchaudio.prototype.models import hifigan_vocoder, hifigan_vocoder_v1, hifigan_vocoder_v2, hifigan_vocoder_v3
  from torchaudio.prototype.pipelines import HIFIGAN_VOCODER_V3_LJSPEECH
  from torchaudio_unittest.common_utils import TestBaseMixin, torch_script
  from .original.env import AttrDict
  from .original.meldataset import mel_spectrogram
  from .original.models import Generator
label_desc: Use image node_id 8 for calling the HiFiGANTestImpl obj's underlying member method code with example usage: obj.test_output_shape_forward() without return types