code: def test_elasticsearch_io_dataset():
      """Test the functionality of the ElasticsearchIODataset"""
  
      dataset = tfio.experimental.elasticsearch.ElasticsearchIODataset(
          nodes=[NODE], index=INDEX, doc_type=DOC_TYPE, headers=HEADERS
      )
  
      assert issubclass(type(dataset), tf.data.Dataset)
  
      for item in dataset:
          for attr in ATTRS:
              assert attr in item
  
file_path: io/tests/test_elasticsearch.py
imports: import time
  import json
  import pytest
  import socket
  import requests
  import tensorflow
  from tensorflow import feature_column
  from tensorflow.keras import layers
  import tensorflow_io
label_desc: Use image node_id 4 for calling a global function with example usage: test_elasticsearch_io_dataset() without return types