public function shorten(): string
    {
        // Shorten only what is longer than the length
        if (strlen($this->string) < $this->length) {
            return $this->string;
        }

        // Shorten string by length
        $this->result = substr($this->string, 0, $this->length);

        // Shorten further until last occurence of a ' '
        $string = substr($this->result, 0, strrpos($this->result, $this->endstring));

        if (!empty($this->wrap_url)) {
            $addition = '<a href="' . $this->wrap_url . '">' . $this->addition . '</a>';
        }

        // Add addition
        $this->result .= $addition;

        // Done.
        return $this->result;
    }