While trying to recreate the history tree of a given revision id it appears that the edges having id as source are not returned by graph.visit_edges when graph is a NaiveClient (used for testing in swh-provenance):
parents = {}
src = CoreSWHID(object_type=ObjectType.REVISION, object_id=id)
request = graph.visit_edges(str(src), edges="rev:rev")
for child, parent in request:
parents.setdefault(
CoreSWHID.from_string(child).object_id, []
).append(CoreSWHID.from_string(parent).object_id)
assert src.object_id in parents