From a32e0297508091db5c4cf23f4fd0db8a2637c5ca Mon Sep 17 00:00:00 2001
From: JerryYanWan <ywanad@connect.ust.hk>
Date: Fri, 7 Apr 2017 11:03:27 +0800
Subject: [PATCH] remove Array[Future]; make it run in single thread