@Override
		public ToolTipInfo<?> getToolTipInfo(MouseEvent event) {

			// check for a vertex hit first, otherwise, we get edge hits when we are hovering
			// over a vertex, due to how edges are interpreted as existing all the way to the
			// center point of a vertex
			AttributedVertex vertex = getVertex(event);
			if (vertex != null) {
				return new AttributedToolTipInfo(vertex, event);
			}

			AttributedEdge edge = getEdge(event);
			if (edge != null) {
				return new AttributedToolTipInfo(edge, event);
			}

			// no vertex or edge hit; just create a basic info that is essentially a null-object
			// placeholder to prevent NPEs
			return new AttributedToolTipInfo(vertex, event);
		}
Removes all externally added actions. This is called before re-using the graph window for a
new graph which may add its own set of actions for that particular graph.
Ghidra/Features/GraphServices/src/main/java/ghidra/graph/visualization/DefaultGraphDisplay.java