private static void listContactsWithDetail(List<Contact> contacts) {
        System.out.println("");
        System.out.println("Listing contacts with details:");
        for (Contact contact : contacts) {
            System.out.println(contact);
            if (contact.getContactTelDetails() != null) {
                for (ContactTelDetail contactTelDetail : contact.getContactTelDetails()) {
                    System.out.println(contactTelDetail);
                }
            }
            if (contact.getHobbies() != null) {
                for (Hobby hobby : contact.getHobbies()) {
                    System.out.println(hobby);
                }
            }
            System.out.println();
        }
    }