public function getSshUrls()
    {
        $prefix = 'pf:ssh:';
        $prefixLength = strlen($prefix);
        $sshUrls = [];
        foreach ($this->data['_links'] as $rel => $link) {
            if (strpos($rel, $prefix) === 0 && isset($link['href'])) {
                $sshUrls[substr($rel, $prefixLength)] = $this->convertSshUrl($link['href']);
            }
        }
        if (empty($sshUrls) && $this->hasLink('ssh')) {
            $sshUrls[''] = $this->convertSshUrl($this->getLink('ssh'));
        }

        return $sshUrls;
    }