'Deletes all tag definitions within a namespace.
For a full list of available parameters, please refer to the official
API reference:
http://developer.openstack.org/api-ref/image/v2/metadefs-index.html#delete-all-tag-definitions'

def delete_namespace_tags(self, namespace):

    url = ('metadefs/namespaces/%s/tags' % namespace)
    (resp, _) = self.delete(url)
    self.expected_success([200, 204], resp.status)
    return rest_client.ResponseBody(resp)
