private function validateLowerThan(): bool
    {
        if ($this->options['inclusive'] === true) {
            $isValid = \mb_strlen($this->value, 'UTF-8') <= $this->options['length'] ? true : false;
            if (!$isValid) {
                $this->setError(self::VALIDATOR_ERROR_STRING_LENGTH_MUST_BE_LOWER_OR_EQUAL_TO_MAX);
            }
            return $isValid;
        }

        $isValid = \mb_strlen($this->value, 'UTF-8') < $this->options['length'] ? true : false;
        if (!$isValid) {
            $this->setError(self::VALIDATOR_ERROR_STRING_LENGTH_MUST_BE_LOWER_THAN_MAX);
        }
        return $isValid;
    }