public void unionWith(DirectedGraph otherGraph) {
		GraphIterator<Vertex> vi = otherGraph.vertexIterator();
		while (vi.hasNext()) {
			add(vi.next());
		}
		GraphIterator<Edge> ei = otherGraph.edgeIterator();
		while (ei.hasNext()) {
			add(ei.next());
		}
	}
Creates union of graphs in place by adding all vertices and edges of
other graph to this graph. This method used to return a different graph
as the union but now does not.
Ghidra/Framework/Generic/src/main/java/ghidra/util/graph/DirectedGraph.java