private static String combineIds(Collection<AttributedVertex> vertices) {
		return vertices.stream().map(AttributedVertex::getName).collect(Collectors.joining("\n"));
	}
Returns a set of vertices such that all non-group nodes in the given vertices are included
and any group nodes in the given vertices are replaced with their contained vertices.

@param vertices the collection of vertices to flatten into a set of non-group vertices.
@return a set of non-group vertices derived from the given collection where all the group
vertices have been replace with their contained vertices.
Ghidra/Features/GraphServices/src/main/java/ghidra/graph/visualization/GroupVertex.java