public void programClosed() {

		programArchive.getDataTypeManager().removeDataTypeManagerListener(listenerDelegate);
		dataTypeIndexer.removeDataTypeManager(programArchive.getDataTypeManager());
		openArchives.remove(programArchive);
		fireArchiveClosed(programArchive);
		programArchive = null;
	}
Notification that the program is closed. Remove the root category
for the program from the provider.
Ghidra/Features/Base/src/main/java/ghidra/app/plugin/core/datamgr/archive/DataTypeManagerHandler.java