Explorers aren't the right abstraction. For the purposes of displaying svg files we don't care in which order do we explore the nodes. We may care about this for other analyses, but we're not there yet.
The function of cutting out chunks of the graph is performed poorly by the explorers, because querying predecessors/successors on the explored nodes yields original successors/predecessors even if they aren't being explored.
Introduce a new entity, "trimmers", that do one thing but to it right: cut out chunks of the graph. Trimmers mutate the graph, so stale edges aren't even visible to their consumers in the pipeline. Additionally, trimmers are intrinsically composable: multiple trimmers can be applied to the graph sequentially.
Refactor the single-path explorer into the single-path trimmer. Rename the test file for consistency.