context Zone {
  constraint HasName {
      check : self.name.isDefined()
      message : 'Mistake'
  }
}

context Host {
  constraint test2 {
      check : true
      message : 'Mistake2'
  }

  constraint  test3 {
      check : false
      message : 'Mistake3'
  }

  constraint test4 {
      check : return true
      message : 'Mistake4'
  }

  constraint test4 {
      check : return false
      message : 'Mistake5'
  }

}

@namespace(
	uri="firewalls",
	prefix="firewalls")
package firewalls;

@gmf.diagram(foo="bar")
class Diagrama{
   val Zone[*] zonas;
   val Firewall[*] firewalls;
   val Estructura[*] estructuras;
}

@gmf.node(label = "nombre_host")
class Host{
	attr String nombre_host;
}

@gmf.node(label = "nombre_server")
class Server{
	attr String nombre_server;
}

@gmf.node(label = "name")
class Zone{
	attr String name;
   	@gmf.compartment(foo="bar")
   	val Host[*] host;
   	@gmf.compartment(foo="bar")
   	val Server[*] servers;
}

@gmf.node(label = "name")
class Firewall {
   attr String name;
}

@gmf.link(source="source", target="target", style="dot", width="2")
class Estructura{
   ref Firewall source;
   ref Zone target;
}