code: protected boolean isExistingTransaction(Object transaction) {
          ContextSourceAndHibernateTransactionObject actualTransactionObject = (ContextSourceAndHibernateTransactionObject) transaction;
  
          return super.isExistingTransaction(actualTransactionObject
                  .getHibernateTransactionObject());
      }
docs: /*
  @see org.springframework.orm.hibernate5.HibernateTransactionManager#isExistingTransaction(java.lang.Object)