public void voucherCodeGenerator(String key) {
		// provide an algorithm to generate a valid voucher Code based on the given key.
		// hard code here for demo
		List<String> voucherCodeToGenerate = new ArrayList<String>();
		for(int i = 1; i <= 5; i++) {
			voucherCodeToGenerate.add("voucherCode" + key + i);
		}
		setVoucherList(voucherCodeToGenerate);
	}