class_docstr: Utility class to facilitate API queries and state management of
  session data.
code: def __init__(self, nodes, index, doc_type, headers_dict):
      self.nodes = nodes
      self.index = index
      self.doc_type = doc_type
      self.headers_dict = headers_dict
      self.prepare_base_urls()
      self.prepare_connection_data()
  
file_path: io/tensorflow_io/python/experimental/elasticsearch_dataset_ops.py
imports: from urllib.parse import urlparse
  import tensorflow
  from tensorflow_io.python.ops import core_ops
  from tensorflow_io.python.experimental import serialization_ops
label_desc: Use image node_id 1 to create a new _ElasticsearchHandler object  with example: obj = _ElasticsearchHandler(nodes, index, doc_type, headers_dict)