code: def test_dataset_with_audio_feature_with_none():
      data = {"audio": [None]}
      features = Features({"audio": Audio()})
      dset = Dataset.from_dict(data, features=features)
      item = dset[0]
      assert item.keys() == {"audio"}
      assert item["audio"] is None
      batch = dset[:1]
      assert len(batch) == 1
      assert batch.keys() == {"audio"}
      assert isinstance(batch["audio"], list) and all(
          item is None for item in batch["audio"]
      )
      column = dset["audio"]
      assert len(column) == 1
      assert isinstance(column, list) and all(
          item is None for item in column
      )
  
      # nested tests
  
      data = {"audio": [[None]]}
      features = Features({"audio": Sequence(Audio())})
      dset = Dataset.from_dict(data, features=features)
      item = dset[0]
      assert item.keys() == {"audio"}
      assert all(i is None for i in item["audio"])
  
      data = {"nested": [{"audio": None}]}
      features = Features({"nested": {"audio": Audio()}})
      dset = Dataset.from_dict(data, features=features)
      item = dset[0]
      assert item.keys() == {"nested"}
      assert item["nested"].keys() == {"audio"}
      assert item["nested"]["audio"] is None
  
imports: import os
  import tarfile
  import pyarrow
  import pytest
  from datasets import Dataset, concatenate_datasets, load_dataset
  from datasets.features import Audio, Features, Sequence, Value
  from ..utils import require_sndfile
label_desc: Use image node_id 17 for calling a global function with example usage: test_dataset_with_audio_feature_with_none() without return types