protected V getVertex(MouseEvent e) {
		VisualizationViewer<V, E> viewer = getViewer(e);
		return JgtUtils.getVertex(e, viewer);
	}
Returns the vertex if the mouse event is over a vertex
@param e the event
@return a vertex or null
Ghidra/Features/GraphServices/src/main/java/ghidra/graph/visualization/mouse/AbstractJgtGraphMousePlugin.java