Vala: Object property.

vala/property/property.vala

@@ -1,5 +1,10 @@
+public class Prop : Object {
+  public int prop;
+}
+
 public class Person : Object {
-    public string height { get; set; default = null; }
+  public string height { get; set; default = null; }
+  public Prop prop {get; set;}
 }
 
 void main () {