public static function getCenterOfMarkers($markers)
    {
        $coords = [];
        foreach ($markers as $marker) {
            if (!($marker instanceof Marker)) {
                throw new InvalidParamException('$markers must be an array of "' . self::className() . '" objects');
            }
            $coords[] = $marker->position;
        }

        return LatLng::getCenterOfCoordinates($coords);
    }