private boolean hasSelection() {
		return !(viewer.getSelectedVertices().isEmpty() && viewer.getSelectedEdges().isEmpty());
	}
Ungroup the selected vertices. If the focusedVertex is no longer in the graph, null it. This
will happen if the focusedVertex was the GroupVertex
Ghidra/Features/GraphServices/src/main/java/ghidra/graph/visualization/DefaultGraphDisplay.java