It isn’t clear what nodes the cost function will be called on...

[stripes]

So the doc comments on the cost don’t make it clear that it is only called on adjacent nodes (and I’m mostly guessing this is true). It is probably important to note because local costs can be easy to do exactly, but it can be much harder to do no -local costs!

So it would be nice if cost noted it only is passed adjacent nodes, and estimatedCost notes it can be asked to estimate a cost to any node.