@Override
	public void dispose() {

		unregisterNavigatable();
		disposed = true;
		for (NavigatableRemovalListener listener : navigationListeners) {
			listener.navigatableRemoved(this);
		}

		super.dispose();

		controller.cleanup();
		if (currentProgram != null) {
			currentProgram.removeListener(this);
			currentProgram = null;
		}
	}
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