CanonicalSet example

Sample.java

private CanonicalSet<relation> repository = 
       CanonicalSet.newInstance(Relation.class);

    public Relation getSharedInstance(Relation relation) {
        if (active) {
            //following method is not in set interface. it returns the equivalent object from set for the given relation
            final ImmutableRelation immutableRelation = new ImmutableRelation(relation);
            return repository.unique(immutableRelation);
        } else {
            return relation;
        }
    }