在zendframework 3中替换zendframework 2的Zend_Validate_Db_RecordExists类是什么？

Question

我正在使用zend Framework 3，并希望检查数据库中是否已存在电子邮件地址，但是我的代码在zendframework 2中。zendframework 3中zendframework 2的Zend_Validate_Db_RecordExists的替代品是什么？

    //Check that the email address exists in the database
    $validator = new Zend_Validate_Db_RecordExists('users', 'emailaddress');
    if ($validator->isValid($emailaddress)) {
        // email address appears to be valid
    } else {
        // email address is invalid; print the reasons
        foreach ($validator->getMessages() as $message) {
            echo "$message\n";
        }
    }

    //Check that the email address exists in the database
    $validator = new Zend_Validate_Db_RecordExists('users', 'emailaddress');
    if ($validator->isValid($emailaddress)) {
        // email address appears to be valid
    } else {
        // email address is invalid; print the reasons
        foreach ($validator->getMessages() as $message) {
            echo "$message\n";
        }
    }