1. State Key Laboratory for Novel Software Technology, Department of Computer Science and Technology, Nanjing University, Nanjing, China
2. Department of Computing, Macquarie University, Sydney, Australia
3. College of Big Data and Intelligent Engineering, Southwest Forestry University, Kunming, China
4. M3S Empirical Software Engineering Research Unit, University of Oulu, Oulu, Finland
5. College of Computer Science and Technology, China University of Petroleum East China - Qingdao Campus, Qingdao, China