docstr: `self._save` can save audio with many channels
docstr_tok: ["`","self._save","`","can","save","audio","with","many","channels"]
code: def test_save_multi_channels(self, num_channels):
      """`self._save` can save audio with many channels"""
      self.assert_save_consistency(
          "wav",
          encoding="PCM_S",
          bits_per_sample=16,
          num_channels=num_channels,
      )
  
imports: import io
  import os
  import pathlib
  import subprocess
  import sys
  from functools import partial
  from typing import Optional
  import torch
  from parameterized import parameterized
  from torchaudio._backend.ffmpeg import _parse_save_args
  from torchaudio._backend.utils import get_save_func
  from torchaudio.io import CodecConfig
  from torchaudio_unittest.backend.dispatcher.sox.common import get_enc_params, name_func
  from torchaudio_unittest.common_utils import disabledInCI, get_wav_data, load_wav, nested_params, PytorchTestCase, save_wav, skipIfNoExec, skipIfNoFFmpeg, TempDirMixin, TorchaudioTestCase
label_desc: Use image node_id 7 for calling the SaveTest obj's underlying member method code with example usage: obj.test_save_multi_channels(num_channels) without return types