public Vertex[] topologicalSort() {
		return finishListInReverseOrder.toArray(new Vertex[finishListInReverseOrder.size()]);
	}
Returns a topological sort of the directed graph. 
Return the vertices in the explored 
portion of the graph with the following
property:
<ol>
<li>{@literal If the graph is acyclic then v[i] -> v[j] => i < j .}</li>
<li>If the graph contains cycles, then the above is true except when
    (v[i],v[j]) is a back edge.</li>
</ol>
Ghidra/Framework/Generic/src/main/java/ghidra/util/graph/DepthFirstSearch.java