1. Tsinghua Shenzhen International Graduate School, Tsinghua University, 12442 Shenzhen, Guangdong, China
2. Tencent YouTu Lab, Tencent, 508929 Shenzhen, Guangdong, China
3. Department of Statistical Science, University College London, London, United Kingdom of Great Britain and Northern Ireland, WC1E 6BT
4. Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen, Guangdong, China