def import_from_storage_bucket(self, bucket, file, namespace=None, entity_filter=None, labels=None):
        """
        Import a backup from Cloud Storage to Cloud Datastore.

        .. note::
            Keep in mind that this requests the Admin API not the Data API.

        .. seealso::
            https://cloud.google.com/datastore/docs/reference/admin/rest/v1/projects/import

        :param bucket: The name of the Cloud Storage bucket.
        :type bucket: str
        :param file: the metadata file written by the projects.export operation.
        :type file: str
        :param namespace: The Cloud Storage namespace path.
        :type namespace: str
        :param entity_filter: specify which kinds/namespaces are to be imported.
        :type entity_filter: dict
        :param labels: Client-assigned labels.
        :type labels: dict of str
        :return: a resource operation instance.
        :rtype: dict
        """
        admin_conn = self.get_conn()

        input_url = 'gs://' + '/'.join(filter(None, [bucket, namespace, file]))
        if not entity_filter:
            entity_filter = {}
        if not labels:
            labels = {}
        body = {
            'inputUrl': input_url,
            'entityFilter': entity_filter,
            'labels': labels,
        }
        resp = (admin_conn
                .projects()
                .import_(projectId=self.project_id, body=body)
                .execute(num_retries=self.num_retries))

        return resp
Import a backup from Cloud Storage to Cloud Datastore.

        .. note::
            Keep in mind that this requests the Admin API not the Data API.

        .. seealso::
            https://cloud.google.com/datastore/docs/reference/admin/rest/v1/projects/import

        :param bucket: The name of the Cloud Storage bucket.
        :type bucket: str
        :param file: the metadata file written by the projects.export operation.
        :type file: str
        :param namespace: The Cloud Storage namespace path.
        :type namespace: str
        :param entity_filter: specify which kinds/namespaces are to be imported.
        :type entity_filter: dict
        :param labels: Client-assigned labels.
        :type labels: dict of str
        :return: a resource operation instance.
        :rtype: dict