def METHOD_NAME(self, available_backends, expected_backend):
    src = torch.zeros((2, 10))
    filename = "test.wav"
    format = "wav"
    sample_rate = 16000
    with patch("torchaudio._backend.utils.get_available_backends", return_value=available_backends), patch(
        f"torchaudio._backend.utils.{expected_backend.__name__}.save"
    ) as mock_save:
        get_save_func()(filename, src, sample_rate, format=format)
        mock_save.assert_called_once_with(filename, src, sample_rate, True, format, None, None, 4096)