public function isValid($value)
    {
        if (version_compare(VersionNumberUtility::getCurrentTypo3Version(), '7.6.0', '<')) {
            throw new UnsupportedVersionException(
                'The validator "' . self::class . '" cannot be used in TYPO3 versions anterior to `7.6.0`.',
                1506281412
            );
        }

        $value = (string)$value;

        if (false === $this->getIconRegistry()->isRegistered($value)) {
            $errorMessage = $this->translateErrorMessage('validator.icon_exists.not_valid', 'configuration_object', [$value]);
            $this->addError($errorMessage, 1506272737);
        }
    }