@Override
        public void destroy(final Collection<Pair<GeoPrimitive, Object>> values) {
            Log.i(this.logPraefix + "DESTROY " + values.size() + " values");

            if (providerLayer != null) {
                providerLayer.destroy(values);
            }
        }
Key class to be used for entries in MapWriter from a GeoGroup
main/src/main/java/cgeo/geocaching/unifiedmap/geoitemlayer/GeoItemLayer.java