docstr: `self._save` can save sph format.
docstr_tok: ["`","self._save","`","can","save","sph","format","."]
code: def assert_sphere(self, dtype, sample_rate, num_channels):
      """`self._save` can save sph format."""
      self._assert_non_wav("nist", dtype, sample_rate, num_channels)
  
imports: import io
  from functools import partial
  from unittest.mock import patch
  from torchaudio._backend.utils import get_save_func
  from torchaudio._internal import module_utils
  from torchaudio_unittest.common_utils import get_wav_data, load_wav, nested_params, PytorchTestCase, skipIfNoModule, TempDirMixin
  from .common import fetch_wav_subtype, parameterize, skipIfFormatNotSupported
label_desc: Use image node_id 4 for calling the SaveTestBase obj's underlying member method code with example usage: obj.assert_sphere(dtype, sample_rate, num_channels) without return types