class Realm(object):
    implements(portal.IRealm)

    def __init__(self, DSage):
        self.DSage = DSage

    def requestAvatar(self, avatarId, mind, *interfaces):
        if not pb.IPerspective in interfaces:
            raise NotImplementedError, "No supported avatar interface."
        else:
            if avatarId == 'admin':
                avatar = AdminPerspective(self.DSage)
            else:
                avatar = UserPerspective(self.DSage)
        avatar.attached(mind)

        return pb.IPerspective, avatar, lambda a=avatar:a.detached(mind)