code: public static int deleteOrphans(EntityManager em) {
          requireArgument(em != null, "Entity manager cannot be null.");
  
          Query query = em.createNamedQuery("Audit.cullOrphans");
  
          return query.executeUpdate();
      }
docs: Finds all audits.
  
  @param   em  Entity manager. Cannot be null.
  
  @return  All audits