def delete_all_objects(self, nms, async_=False):
        """
        Deletes all objects from this container.

        By default the call will block until all objects have been deleted. By
        passing True for the 'async_' parameter, this method will not block, and
        instead return an object that can be used to follow the progress of the
        deletion. When deletion is complete the bulk deletion object's
        'results' attribute will be populated with the information returned
        from the API call. In synchronous mode this is the value that is
        returned when the call completes. It is a dictionary with the following
        keys:

            deleted - the number of objects deleted
            not_found - the number of objects not found
            status - the HTTP return status code. '200 OK' indicates success
            errors - a list of any errors returned by the bulk delete call
        """
        if nms is None:
            nms = self.api.list_object_names(self.name, full_listing=True)
        return self.api.bulk_delete(self.name, nms, async_=async_)