public void zoomInOut(final boolean zoomIn) {
        mMap.animator().animateZoom(300, zoomIn ? 2 : 0.5, 0f, 0f);
    }
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