I. Introduction
Graphs are powerful representations for modeling complex relationships and structures in various domains, ranging from social networks and biological networks, to recommendation systems and knowledge graphs. Graph generative models aim to capture the underlying patterns, connectivity, and features present in real-world graphs, and generate new graph instances that exhibit similar characteristics. The ability to generate realistic and diverse graphs is of great importance in understanding and analyzing real-world phenomena, and it has been applied to code completion [1], materials design [2], and drug discoveries [3].