code: def test_convert_value_empty_sequence():
      assert huggingface_dataset_builder._convert_value(
          [None, "string"], feature_lib.Sequence(feature=np.str_)
      ) == [b"", "string"]
  
imports: import datetime
  from unittest import mock
  from absl import logging
  import numpy
  import pytest
  import tensorflow
  from tensorflow_datasets.core import features
  from tensorflow_datasets.core import lazy_imports_lib
  from tensorflow_datasets.core import registered
  from tensorflow_datasets.core.dataset_builders import huggingface_dataset_builder
label_desc: Use image node_id 8 for calling a global function with example usage: test_convert_value_empty_sequence() without return types