@Override
	public AttributedVertex addVertex() {
		AttributedVertex vertex = super.addVertex();
		vertexMap.put(vertex.getId(), vertex);
		return vertex;
	}
Adds a new vertex with the given id and name.  If a vertex already exists with that id,
then that vertex will be returned, but with its name changed to the given name.

@param id the unique vertex id that the graph should have a vertex for.
@param vertexName the name to associate with this vertex
@return either an existing vertex with that id, or a newly added vertex with that id
Ghidra/Framework/Graph/src/main/java/ghidra/service/graph/AttributedGraph.java