1. College of Computer Science and Electronic Engineering, Hunan University, Changsha, China
2. Research Center for Graph Computing, Zhejiang Lab, Hangzhou, China
3. Department of Computer Science, College of Engineering, Mathematics, and Physical Sciences, University of Exeter, Exeter, U.K.
4. Research Division of Distributed Systems, TU Wien, Vienna, Austria
5. Department of Computing, The Hong Kong Polytechnic University, Hung Hom, Hong Kong