code: public Wife addWifeToFamily(final Family family, final Person person) {
          if (family == null || person == null) {
              return new Wife();
          }
          final FamS famS = new FamS(person, "FAMS",
                  new ObjectId(family.getString()));
          final Wife wife = new Wife(family, "Wife",
                  new ObjectId(person.getString()));
          family.insert(wife);
          person.insert(famS);
          return wife;
      }
docs: Add a person as the wife in a family.
  
  @param family the family
  @param person the person
  @return the wife object