def list_notifications(self, client=None):
        """List Pub / Sub notifications for this bucket.

        See:
        https://cloud.google.com/storage/docs/json_api/v1/notifications/list

        If :attr:`user_project` is set, bills the API request to that project.

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

        :rtype: list of :class:`.BucketNotification`
        :returns: notification instances
        """
        client = self._require_client(client)
        path = self.path + "/notificationConfigs"
        iterator = page_iterator.HTTPIterator(
            client=client,
            api_request=client._connection.api_request,
            path=path,
            item_to_value=_item_to_notification,
        )
        iterator.bucket = self
        return iterator
List Pub / Sub notifications for this bucket.

        See:
        https://cloud.google.com/storage/docs/json_api/v1/notifications/list

        If :attr:`user_project` is set, bills the API request to that project.

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

        :rtype: list of :class:`.BucketNotification`
        :returns: notification instances