jsf/subsystem/src/main/java/org/jboss/as/jsf/deployment/JSFModuleIdFactory.java
private void loadIdsManually() {
        implIds.put("main", ModuleIdentifier.create(IMPL_MODULE));
        apiIds.put("main", ModuleIdentifier.create(API_MODULE));
        injectionIds.put("main", ModuleIdentifier.create(INJECTION_MODULE));

        allVersions.add("main");

        activeVersions.add("main");
    }
private void loadIdsManually() {
        implIds.put("main", ModuleIdentifier.create(IMPL_MODULE));
        apiIds.put("main", ModuleIdentifier.create(API_MODULE));
        injectionIds.put("main", ModuleIdentifier.create(INJECTION_MODULE));

        allVersions.add("main");

        activeVersions.add("main");
    }
just provide the default implementations