@base.remotable
    def refresh(self):
        current = self.__class__.get_by_uuid(self._context, self.uuid)
        for field in self.fields:
            if self.obj_attr_is_set(field) and self[field] != current[field]:
                self[field] = current[field]
        self.obj_reset_changes()
Implements :func:`autobahn.wamp.interfaces.ISession.onJoin`
dataset/ETHPy150Open BU-NU-CLOUD-SP16/Trusted-Platform-Module-nova/nova/objects/instance_group.py/InstanceGroup.refresh--crossover with--dataset/ETHPy150Open crossbario/autobahn-python/autobahn/wamp/protocol.py/ApplicationSession.onJoin