Geolocator plugin not working

Hi,

   I need this plugin.  And I'm using or testing this code https://components.xamarin.com/view/geolocatorplugin and it doesn't work.  My xamarin studion is 5.7.2 (Indie).

  string tmpAdress;

var myAddress = "394 Pacific Ave, San Francisco, California";
var approximateLocation = await _geoCoder.GetPositionsForAddressAsync (myAddress);

        foreach (var p in approximateLocation) {
            tmpAdress += p.Latitude + ", " + p.Longitude + "\n";
        } 

Problem:
It will stop on this code and never execute the next statement . (The foreach loop). It just hangs forever..
var approximateLocation = await _geoCoder.GetPositionsForAddressAsync (myAddress);

please help or let me know..