class Map {
private:
	this() {}
	static Map obj;
	void* list[void*];
public:
	static Map GetInstance() {
		synchronized {
			if (!obj) { obj = new Map; }
		}
		return obj;
	}
	void SetProp(void* key, void* value) {
		list[key] = value;
	}
	void* GetProp(void* key) {
		try {
			return list[key];
		} catch {
			return null;
		}
	}
	void RemoveProp(void* key) {
		if (key in list) {
			list[key] = null;
			list.remove(key);
		}
	}
}