class_docstr: BigQueryClient is the entrypoint for interacting with Cloud BigQuery in TF.
  
  BigQueryClient encapsulates a connection to Cloud BigQuery, and exposes the
  `readSession` method to initiate a BigQuery read session.
docstr: Creates a BigQueryClient to start BigQuery read sessions.
docstr_tok: ["Creates","a","BigQueryClient","to","start","BigQuery","read","sessions","."]
code: def __init__(self):
      """Creates a BigQueryClient to start BigQuery read sessions."""
      self._client_resource = core_ops.io_big_query_client()
  
imports: import collections
  import enum
  import tensorflow
  from operator import itemgetter
  from tensorflow.python.data.ops import dataset_ops
  from tensorflow.python.framework import dtypes
  from tensorflow.python.framework import tensor_spec
  from tensorflow.python.util import deprecation
  from tensorflow_io.python.ops import core_ops
label_desc: Use image node_id 1 to create a new BigQueryClient object  with example: obj = BigQueryClient()