How to open a info windows by default using swift

Question

I have a method like this:

func printMarkers(latlng: CLLocationCoordinate2D, title: String)->Void{
        let marker = GMSMarker()
        marker.position = latlng
        marker.title = title

        marker.map = self.mapView
    }

But, the info windows is closed by default and it's open when I tap over the marker.

How I can open the infowindow by default using swift?