@Override
	public GraphIterator<Vertex> iterator() {
		return new VertexSetIterator();
	}
Return an iterator over all of the vertices in this VertexSet.
The iterator becomes invalid and throws a ConcurrentModificationException
if any changes are made to the VertexSet after the iterator is created.
Ghidra/Framework/Generic/src/main/java/ghidra/util/graph/VertexSet.java