@Override
	public Object getUndoRedoState(DomainObject domainObject) {
		if (domainObject != currentProgram) {
			return null;
		}
		SaveState saveState = new SaveState();
		writeDataState(saveState);
		return saveState;
	}
Tells a plugin that it is no longer needed. The plugin should remove
itself from anything that it is registered to and release any resources.
Ghidra/Features/Base/src/main/java/ghidra/app/plugin/core/programtree/ProgramTreePlugin.java