@Override
		public URL getURLFromID(ID id) throws MalformedURLException {
			URL URL = mapDelegate.getURLFromID(id);
			if (URL != null) {
				return URL; // it's in our map
			}

			Set<Entry<HelpSet, Map>> entrySet = helpSetsToCombinedMaps.entrySet();
			for (Entry<HelpSet, Map> entry : entrySet) {
				Map map = entry.getValue();
				URL = map.getURLFromID(id);
				if (URL != null) {
					return URL;
				}
			}

			LOG.trace("No URL found in any HelpSet for ID: " + id);

			URL = tryToCreateURLFromID(id.id);
			if (URL != null) {
				return URL;
			}

			return null;
		}
A special class to allow us to handle help ID lookups across help sets
Ghidra/Framework/Help/src/main/java/help/GHelpSet.java