public static Set<?> verts2referentSet(Collection<Vertex> verts) {
		Set<Object> s = new HashSet<>();
		Iterator<Vertex> vIter = verts.iterator();
		while (vIter.hasNext()) {
			Vertex vert = vIter.next();
			s.add(vert.referent());
		}
		return s;
	}
This method converts a collection of verticies into a set of its
referent objects.  It is up to the methods using the created set 
to properly type cast the set's elements.

@param verts the vertices
@return the set of referent objects
Ghidra/Framework/Generic/src/main/java/ghidra/util/graph/DirectedGraph.java