Add lines on google map aip android

  private void addLines(LatLng arg0) {

        if(latPrevious==null) {
            latPrevious=arg0;
        }else
        {PolylineOptions optionLine = new PolylineOptions();
            optionLine.add(latPrevious);
            optionLine.add(arg0);
            Polyline line = mMap.addPolyline(optionLine);
            line.setColor(Color.BLUE);
            line.setWidth(1);

        }
    }