code: def _validate_dataset_table_exist(
      self, project_id: str, dataset: str
  ) -> None:
      from google.api_core import exceptions
      from google.cloud import bigquery
  
      client = bigquery.Client(project=project_id)
      dataset_id = dataset.split(".")[0]
      try:
          client.get_dataset(dataset_id)
      except exceptions.NotFound:
          raise ValueError(
              "Dataset {} is not found. Please ensure that it exists.".format(
                  dataset_id
              )
          )
  
      try:
          client.get_table(dataset)
      except exceptions.NotFound:
          raise ValueError(
              "Table {} is not found. Please ensure that it exists.".format(
                  dataset
              )
          )
  
file_path: ray/python/ray/data/datasource/bigquery_datasource.py
imports: import logging
  from typing import List, Optional
  from ray.data._internal.util import _check_import
  from ray.data.block import Block, BlockMetadata
  from ray.data.datasource.datasource import Datasource, ReadTask
  from ray.util.annotations import PublicAPI
label_desc: Use image node_id 4 for calling the BigQueryDatasource obj's underlying member method code with example usage: obj._validate_dataset_table_exist(project_id, dataset) without return types