API call:  test for the existence of the job via a GET request

        See
        https://cloud.google.com/bigquery/docs/reference/rest/v2/jobs/get

        :type client: :class:`~google.cloud.bigquery.client.Client` or
                      ``NoneType``
        :param client: the client to use.  If not passed, falls back to the
                       ``client`` stored on the current dataset.

        :type retry: :class:`google.api_core.retry.Retry`
        :param retry: (Optional) How to retry the RPC.

        :rtype: bool
        :returns: Boolean indicating existence of the job.

def exists(self, client=None, retry=DEFAULT_RETRY):
        """API call:  test for the existence of the job via a GET request

        See
        https://cloud.google.com/bigquery/docs/reference/rest/v2/jobs/get

        :type client: :class:`~google.cloud.bigquery.client.Client` or
                      ``NoneType``
        :param client: the client to use.  If not passed, falls back to the
                       ``client`` stored on the current dataset.

        :type retry: :class:`google.api_core.retry.Retry`
        :param retry: (Optional) How to retry the RPC.

        :rtype: bool
        :returns: Boolean indicating existence of the job.
        """
        client = self._require_client(client)

        extra_params = {"fields": "id"}
        if self.location:
            extra_params["location"] = self.location

        try:
            client._call_api(
                retry, method="GET", path=self.path, query_params=extra_params
            )
        except NotFound:
            return False
        else:
            return True