Powermail check if value is same in other fields, like for email double validation

EmailValidator.php

<?php

namespace VENDOR\EXT\Domain\Powermail;

use In2code\Powermail\Domain\Model\Mail;
use In2code\Powermail\Domain\Validator\AbstractValidator;
use TYPO3\CMS\Core\Utility\GeneralUtility;
use TYPO3\CMS\Extbase\Error\Result;

class EmailValidator extends AbstractValidator
{

    protected $configuration = [];

    /**
     *
     * @param Mail $mail
     * @return bool
     */
    public function isValid($mail)
    {
        $result = new Result();
        if ((int)$this->configuration['form'] === $mail->getForm()->getUid()) {
            $answerValues = [];
            $firstAnswerField = null;
            $fields = GeneralUtility::trimExplode(',', $this->configuration['emailFields'], true);
            foreach ($mail->getAnswers() as $answer) {
                if ($firstAnswerField === null) {
                    $firstAnswerField = $answer->getField();
                }
                if (in_array($answer->getField()->getMarker(), $fields, true)) {
                    $answerValues[] = $answer->getValue();
                }
            }

            if (count($answerValues) > 1) {
                $isSame = true;
                foreach ($answerValues as $value) {
                    if ($value !== $answerValues[0]) {
                        $isSame = false;
                    }
                }
                if (!$isSame) {
                    $this->setErrorAndMessage($firstAnswerField, 'Email-Adresse ist nicht ident');
                }
            }
        }
        return $this->isValidState();
    }
}

powermail.typoscript

plugin.tx_powermail.settings.setup {
        validators {
                1 {
                        # Classname that should be called with method *Validator()
                        class = VENDOR\EXT\Domain\Powermail\EmailValidator

                        # optional: Add configuration for your PHP
                        config {
                                emailFields = e_mail,email2
                                form = 1
                        }
                }
        }
}