public void writeDataState(SaveState saveState) {

		// navigatable stuff
		saveState.putLong("NAV_ID", getInstanceID());

		if (!controller.hasResults()) {
			return;
		}

		if (currentLocation != null) {
			currentLocation.saveState(saveState);
		}

		GraphPerspectiveInfo<FGVertex, FGEdge> info =
			controller.getGraphPerspective(currentLocation);
		info.saveState(saveState);
	}
Returns true when something destructive has happened to the data upon which the graph has
created, like a memory block move.
Ghidra/Features/FunctionGraph/src/main/java/ghidra/app/plugin/core/functiongraph/FGProvider.java