Get all unconnected inputs or outputs in a canonical order

Sorry if this is already possible, but I did not seem to find a documented way to do this.

Is there any way to iterate over all the unconnected inputs or outputs of the graph, in some predictable canonical order?

Furthermore, is the order stable across deletion of nodes or links? Say that a graph contains nodes A, B, C and I know that the inputs of A would be iterated over before the inputs of C. If I then delete B, am I guaranteed that the relative ordering of A's inputs and C's inputs are preserved?

I was developing my own implementation of port graphs before stumbling on this crate, and was thinking of abandoning my own crate to contribute to this one. I have already implemented this feature in my crate, so I would be happy to implement this feature myself.

Start by locating the crate's existing APIs for iterating unconnected inputs and outputs, then inspect how node and link deletion affects iteration order. Define focused tests for canonical ordering and for preserving relative order after deletion; the issue is complete when both behaviors are documented and verified.