@Override
	public List<FGLayoutProvider> findLayouts() {

		List<FGLayoutProvider> list = new ArrayList<>();

		// add discovered layouts
		List<FGLayoutProvider> instances =
			ClassSearcher.getInstances(FGLayoutProvider.class);
		list.addAll(instances);

		// add hand-picked, generated layout providers
		List<String> jgtLayoutNames = JgtLayoutFactory.getSupportedLayoutNames();
		for (String name : jgtLayoutNames) {
			list.add(new JgtNamedLayoutProvider(name));
		}
		return list;
	}
Finds {@link FGLayout}s via the classpath
Ghidra/Features/FunctionGraph/src/main/java/ghidra/app/plugin/core/functiongraph/DiscoverableFGLayoutFinder.java