public function getFlowList()
    {
        $url = 'http://www.oekobaudat.de/OEKOBAU.DAT/resource/flows/?pageSize=20000';
        $xmlString = file_get_contents($url);
        $xmlString = str_replace(array('p:', 'sapi:', 'mm:'), '', $xmlString);
        $flows = \simplexml_load_string($xmlString);

        $result = array();
        foreach ($flows as $flow) {
            $result[(string) $flow->uuid] = (string) $flow->name;
        }

        return $result;
    }