text: refine casetype Command += {
  	MQTT_PUBREL  -> pubrel  : MQTT_pubrel(pdu);
  };
  
  type MQTT_pubrel(pdu: MQTT_PDU) = record {
  	msg_id : uint16;
  } &let {
  	proc: bool = $context.flow.proc_mqtt_pubrel(this, pdu.is_orig);
  };
  
  refine flow MQTT_Flow += {
  	function proc_mqtt_pubrel(msg: MQTT_pubrel, is_orig: bool): bool
  		%{
  		if ( mqtt_pubrel )
  			{
  			BifEvent::enqueue_mqtt_pubrel(connection()->bro_analyzer(),
  			                              connection()->bro_analyzer()->Conn(),
  			                              is_orig,
  			                              ${msg.msg_id});
  			}
  		return true;
  		%}
  };
  