code: def dataset_exists(self, dataset):
          
  
          try:
              response = self.client.datasets().get(projectId=dataset.project_id,
                                                    datasetId=dataset.dataset_id).execute()
              if dataset.location is not None:
                  fetched_location = response.get('location')
                  if dataset.location != fetched_location:
                      raise Exception('''Dataset already exists with regional location {}. Can't use {}.'''.format(
                          fetched_location if fetched_location is not None else 'unspecified',
                          dataset.location))
  
          except http.HttpError as ex:
              if ex.resp.status == 404:
                  return False
              raise
  
          return True
docs: Returns whether the given dataset exists.
          If regional location is specified for the dataset, that is also checked
          to be compatible with the remote dataset, otherwise an exception is thrown.
  
             :param dataset:
             :type dataset: BQDataset