@Override
    public void setCenter(final Geopoint geopoint) {
        final MapPosition pos = mMap.getMapPosition();
        pos.setPosition(geopoint.getLatitude(), geopoint.getLongitude());
        mMap.setMapPosition(pos);
    }
call this instead of VTM.layers().add so that we can keep track of layers added by the tile provider
main/src/main/java/cgeo/geocaching/unifiedmap/mapsforgevtm/MapsforgeVtmFragment.java