Difference of readout function in code vs. paper

[Dinxin]

We noticed that the readout function in the original paper is concatenation, while the one in code implementation is addition.

[rusty1s]

This is actually the same, but utilizing transformation and addition is a bit more memory-efficient:

x = self.lin(torch.cat([x1, x2], dim=-1))

is equal to

x = self.lin1(x1) + self.lin(x2)