private void groupSelectedVertices() {
		AttributedVertex vertex = graphCollapser.groupSelectedVertices();
		if (vertex != null) {
			askToNameGroupVertex(vertex);
			focusedVertex = vertex;
			scrollToSelected(vertex);
		}
	}
create the action icon buttons on the upper-right of the graph display window
Ghidra/Features/GraphServices/src/main/java/ghidra/graph/visualization/DefaultGraphDisplay.java