public DHCPOption applyOption(DHCPPacket request) {
		if (request == null) {
			throw new NullPointerException("request is null");
		}
		if (this.mirror) {
			DHCPOption res = request.getOption(this.getCode());
			return (res != null ? res : this);	// return res or this
		} else {
			return this;
		}
	}