Getting specific link when used with multigraph

When used with a multigraph, is there a way to see which specific link the path is using?

For example, when returning multiple paths (https://github.com/anvaka/ngraph.path/issues/6#issue-367392470), in order to know which links to invalidate for subsequent searches, we need to be able to access the links found by the pathfinder.

Start by reading the pathfinder behavior described here and the related multiple-paths discussion in issue #6. Determine how a multigraph path can expose the specific links it uses, and consider the work complete when callers can identify those links for invalidation in subsequent searches.

Written by the indexing model from the issue text.