public void removeAll() {
        requestChange(() -> {
            //clear all existing requests to add/remove
            requestedToAdd.clear();
            requestedToRemove.clear();
            mapChangeProcessQueue.clear();
            //refill pipeline with requests to remove everything which is drawn
            requestedToRemove.addAll(objectMap.keySet());
            for (K o : requestedToRemove) {
                mapChangeProcessQueue.add(new Pair<>(o, false));
            }
        });
    }
removes ALL objects from this Set
main/src/main/java/cgeo/geocaching/utils/AsynchronousMapWrapper.java