code: def test_on_real_audio():
      """Test that metric works on real audio signal."""
      _, ref = wavfile.read(_SAMPLE_AUDIO_SPEECH)
      _, deg = wavfile.read(_SAMPLE_AUDIO_SPEECH_BAB_DB)
      assert torch.allclose(
          signal_distortion_ratio(
              torch.from_numpy(deg), torch.from_numpy(ref)
          ).float(),
          torch.tensor(0.2211),
          rtol=0.0001,
          atol=1e-4,
      )
  
imports: from functools import partial
  from typing import Callable
  import numpy
  import pytest
  import torch
  from mir_eval.separation import bss_eval_sources
  from scipy.io import wavfile
  from torch import Tensor
  from torchmetrics.audio import SignalDistortionRatio
  from torchmetrics.functional import signal_distortion_ratio
  from torchmetrics.utilities.imports import _TORCH_GREATER_EQUAL_1_11
  from unittests import _Input
  from unittests.audio import _SAMPLE_AUDIO_SPEECH, _SAMPLE_AUDIO_SPEECH_BAB_DB, _SAMPLE_NUMPY_ISSUE_895
  from unittests.helpers import seed_all
  from unittests.helpers.testers import MetricTester
label_desc: Use image node_id 4 for calling a global function with example usage: test_on_real_audio() without return types