oslopolicy-policy-generator: what is the namespace to use to get Mgnum policy?

Hi, I'd like to see the default Magnum (Oslo) policy used with Magnum. With other services, I use oslopolicy-policy-generator and use the service name as the namespace but for Magnum, "--namespace magnum" returns an error saying that there is no "magnum" namespace. Does anybody know what is the namespace to use with Magnum? Or how to display the currently active policy, preferably in YAML format? Thanks in advance. Cheers, Michel