docs: @Override
      public List<VariableInstanceLog> findVariableInstances(long processInstanceId) {
          EntityManager em = getEntityManager();
          Query query = em
              .createQuery("FROM VariableInstanceLog v WHERE v.processInstanceId = :processInstanceId ORDER BY date")
                  .setParameter("processInstanceId", processInstanceId);
          return executeQuery(query, em, VariableInstanceLog.class);
      }