public function isValid($value)
    {
        $filePath = GeneralUtility::getFileAbsFileName($value);

        if (false === GeneralUtility::getUrl($filePath)) {
            $errorMessage = $this->translateErrorMessage('validator.file_exists.not_valid', 'configuration_object', [$value]);
            $this->addError($errorMessage, 1510085560);
        }
    }