assumption of numeric node id

[micahscopes]

I noticed that the getSourceIndex and getTargetIndex functions assume a numeric id. Why is this necessary? I've been using non-numeric id's in my project and while I could convert them all to some number, seems like it'd be nice if I didn't need to do that.

https://github.com/micahscopes/WebCola/blob/4aa06a7af9919a1dde3d79f9f0636573aa7df4fa/src/layout.ts#L781-L783

[aneziac]

Running into the same issue here. It was also hard to track down from the somewhat cryptic error message Uncaught (in promise) TypeError: this.neighbours[u] is undefined. I would appreciate an update on this.