code: def test_add_ragged_fields_all_empty(self, dtype):
      # Empty list
      example_data = []
      tensor_info = feature_lib.TensorInfo(
          shape=(
              None,
              None,
          ),
          dtype=dtype,
          sequence_rank=2,
      )
      out = example_serializer._add_ragged_fields(
          example_data, tensor_info
      )
      self.assertRaggedFieldEqual(
          out,
          {
              "ragged_flat_values": (
                  np.zeros(shape=(0,), dtype=np.int64),
                  feature_lib.TensorInfo(shape=(None,), dtype=tf.int64),
              ),
              "ragged_row_lengths_0": (
                  np.zeros(shape=(0,), dtype=np.int64),
                  feature_lib.TensorInfo(shape=(None,), dtype=tf.int64),
              ),
          },
      )
  
imports: from absl.testing import parameterized
  import numpy
  import tensorflow
  from tensorflow_datasets import testing
  from tensorflow_datasets.core import example_serializer
  from tensorflow_datasets.core.features import feature
  from tensorflow_datasets.core.utils import py_utils
label_desc: Use image node_id 8 for calling the ExampleSerializerTest obj's underlying member method code with example usage: obj.test_add_ragged_fields_all_empty(dtype) without return types