public function checkValue(&$value)
    {
        if (is_string($value)) {
            $value = Placeholder::replaceStringsAndComments($value);
            $value = Placeholder::removeCommentPlaceholders($value, true);
            $value = Placeholder::replaceStringPlaceholders($value, true);
            $value = trim($value);

            if ($value !== '') {
                return true;
            } else {
                $this->setIsValid(false);
            }
        } else {
            throw new \InvalidArgumentException(
                "Invalid type '" . gettype($value). "' for argument 'value' given."
            );
        }
    }