protected Set<Pet> getPetsInternal() {
        if (this.pets == null) {
            this.pets = new HashSet<>();
        }
        return this.pets;
    }
Simple JavaBean domain object representing an owner.

@author Ken Krebs
@author Juergen Hoeller
@author Sam Brannen
@author Michael Isvy
src/main/java/org/springframework/samples/petclinic/model/Owner.java