ref: 022590427c22d4a78593f2a115df0abca5a2769f
parent: 3c4bfc6f2ce8af5817f56d80764c274354334d44
author: Zoe Liu <zoeliu@google.com>
date: Tue Jun 19 08:08:55 EDT 2018
Add hierarchical structure in GF group Change-Id: I06fc4b0ad5a45c49e10a9601a2356fbc6e93d6da