tree e776ef1039f6f2da8ae7585171691a01e487dc1d
parent 6f7ba6ccf140bff46c113e3f35aee2871aee6a92
author wu <wu.shaoyong@zte.com.cn> 1540190722 +0800
committer Andrea Campanella <andrea@opennetworking.org> 1540213985 +0000

The output of toDocument() may be null and should be checked before using.

Change-Id: I9b27c2691337feb5dce421f383cf54128e399568