'Update security groups of a specified instance.'

@profiler.trace
def update_instance_security_group(self, instance_id, new_security_group_ids):

    ports = port_list(self.request, device_id=instance_id)
    for p in ports:
        params = {'security_groups': new_security_group_ids}
        port_update(self.request, p.id, **params)
