'Refreshes the instance group.'

@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()
