The online version of this example can be found at
https://techbase.kde.org/Marble/Runners/Parse

Marble uses so-called runners to calculate routes, do reverse geocoding, parse 
files and search for placemarks (cities, addresses, points of interest, ...). 
This tutorial shows how to use the MarbleRunnerManager class to open a .kml (or
.gpx, ...) file and display its structure in a tree view.
