lock  sync.RWMutex
	graph *simple.DirectedAcyclicGraph
	// vertices is a map of type -> namespace -> name -> vertex
	vertices map[vertexType]namespaceVertexMapping

	// destinationEdgeIndex is a map of vertex -> set of destination IDs
	destinationEdgeIndex map[int]*intSet
	// destinationEdgeThreshold is the minimum number of distinct destination IDs at which to maintain an index
	destinationEdgeThreshold int
}

			t.Errorf("expected graph:\n%s\ngot:\n%s", string(e), string(a))
		}
	}
	expectIndex := func(expect map[string][]string) {
		t.Helper()
		actual := map[string][]string{}
		for from, to := range g.destinationEdgeIndex {
			sortedValues := []string{}
			for member, count := range to.members {
				sortedValues = append(sortedValues, fmt.Sprintf("%s=%d", toString(member), count))
			}
			sort.Strings(sortedValues)

		return false, fmt.Errorf("node '%s' cannot get unknown %s %s/%s", nodeName, vertexTypes[startingType], startingNamespace, startingName)
	}

	// Fast check to see if we know of a destination edge
	if r.graph.destinationEdgeIndex[startingVertex.ID()].has(nodeVertex.ID()) {
		return true, nil
	}

	found := false
	traversal := &traverse.VisitingDepthFirst{
		EdgeFilter: func(edge graph.Edge) bool {