“…Graph Neural Networks (GNNs) have achieved state-of-the-art performance in learning over such relational data in various graph-based machine learning tasks, such as node classification, link prediction, and graph classification [9,20,29,61,68,69]. Due to their superior performance, GNNs are now widely used in many applications such as recommendation systems, credit issuing, traffic forecasting, drug discovery, and medical diagnosis [3,7,17,27,37,63].…”