@Override
	protected String getVertexInfoElementName() {
		return GROUPED_VERTEX_INFO_ELEMENT_NAME;
	}
Locates a vertex for the given info <b>without creating that vertex</b>.  This is in 
contrast to {@link #getVertex(FGController, Map)}, which will create a vertex
(and supporting vertices if it is a group).

@param controller the controller of the current graph
@param vertexMap a mapping of hashed addresses to vertices (creating this upfront is more
       efficient when using it over different {@link GroupedVertexInfo} instances.
@return an existing vertex; null if one does not exist
Ghidra/Features/FunctionGraph/src/main/java/ghidra/app/plugin/core/functiongraph/graph/vertex/GroupedVertexInfo.java