@Override
	public void store() {

		Map<Class<? extends Material>, List<Map<String, Object>>> description 
					= new HashMap<Class<? extends Material>, List<Map<String, Object>>>();

		for (Material m : this.stockToList()) {
			Class<? extends Material> c = m.getClass();

			if (description.containsKey(c)) {
				description.get(c).add(m.getDescription());
			} else {
				List<Map<String, Object>> newList = new ArrayList<Map<String, Object>>();
				newList.add(m.getDescription());
				description.put(c, newList);
			}
		}

		ConfigXML.store(description, KEY_STOCK_FILE, KEY_STOCK_VERSION);
	}