protected function computeMarkerInfoWindows(Map $map)
    {
        $infoWinfows = array();

        foreach ($map->getMarkers() as $marker) {
            if ($marker->hasInfoWindow() && !in_array($marker->getInfoWindow(), $infoWinfows)) {
                $infoWinfows[] = $marker->getInfoWindow();
            }
        }

        return $infoWinfows;
    }