code: private void persist(Object entity, KieRuntimeEvent event) { 
          EntityManager em = getEntityManager(event);
          Object tx = joinTransaction(em);
          em.persist(entity);
          leaveTransaction(em, tx);
      }
docs: This method persists the entity given to it.
  </p>
  This method also makes sure that the entity manager used for persisting the entity, joins the existing JTA transaction.
  @param entity An entity to be persisted.