throw exception if lookup fails

jastadd-mquat-base/src/main/jastadd/Navigation.jrag

@@ -263,6 +263,9 @@ aspect Navigation {
       // else, interpret the property as a local one of the current component
       // this might cause an exception of the property can not be resolved
       Optional<Property> property = containingComponent().resolveProperty(qn.getName(0).getName());
+      if (!property.isPresent()) {
+        throw new EvalutationException("cannot resolve property " + qn.toString());
+      }
       return new SoftwareDesignator(new Opt<>(),property.get().createRef());
     } else {