Support Learnable Structural Positional Encoding (LSPE)

[yuehhua]

Since GNN lack of canonical positional information, it reduces the expressiveness of a GNN model and cannot reach ideal task performance. It is a must to support positional encoding for GNN model. Thus, it is a analog to Transformer model.

Learnable Structural Positional Encoding (LSPE) supports positional encoding learning from message-passing network.

Ref. Graph Neural Networks with Learnable Structural and Positional Representations