public static Set<Property> asProperties(Collection<Resource> resources){
  Set<Property> rslt=new HashSet<Property>();
  for (  Resource r : resources) {
    rslt.add(asProperty(r));
  }
  return rslt;
}

public static Set < Property > asProperties ( Collection < Resource > resources ) { Set < Property > rslt = new HashSet < Property > ( ) ; for ( Resource r : resources ) { rslt . add ( asProperty ( r ) ) ; } return rslt ; }
creates a set of properties from a collection of resources .
