private static void checkContentHandlerMaps() {
		if (contentHandlerTypeMap != null) {
			return;
		}

		initContentHandlerMaps();
		ClassSearcher.addChangeListener(contentHandlerUpdateListener);
	}
Get all {@link ContentHandler}s
@return collection of content handlers
Ghidra/Framework/Project/src/main/java/ghidra/framework/data/DomainObjectAdapter.java