public function getSupportedTanMechanisms()
    {
        $segments = $this->findSegments('HIRMS');
        // @todo create method to get reference element from request
        foreach ($segments as $segment) {
            $segment = $this->splitSegment($segment);
            array_shift($segment);
            foreach ($segment as $seg) {
                list($id, $msg) = explode('::', $seg, 2);
                if ("3920" == $id) {
                    if (preg_match_all('/\d{3}/', $msg, $matches)) {
                        return $matches[0];
                    }
                }
            }
        }

        return array();
    }