private void removeStaleProviders(ArrayList<TreeViewProvider> providerList) {
		Map<String, TreeViewProvider> map = new HashMap<>(providerMap);
		for (String treeName : map.keySet()) {
			TreeViewProvider provider = map.get(treeName);
			if (!providerList.contains(provider)) {
				deregisterService(ViewProviderService.class, provider);
				providerMap.remove(treeName);
			}
		}
	}
Read the data for the plugin upon deserialization; reads what should be
the current selection in the tree.
Ghidra/Features/Base/src/main/java/ghidra/app/plugin/core/programtree/ProgramTreePlugin.java