Test dataset #31

Hi, thanks for your work. The code is really hard for me now, could you give me a overall guide for two questions?

1. When a graph in test dataset has a size that does not show in train dataset, the parameters got from the train set don't fit the "unseen" graph, then how the codes work? And I can't even find the test dataset in the codes, just validation dataset, why this?
2. The main way to construct the graph dataset is using networkx module, are there any advantages here? Cause the GCN, GAT,ST-GCN don't use this, they seem to be more brief.
   Thanks.