@Override
    public ResourceConfig register(Class<?> componentClass, Map<Class<?>, Integer> contracts) {
        if (allowedToRegister(componentClass)) {
            resourceConfig.register(componentClass, contracts);
        }
        return resourceConfig;
    }
The implementation delegates to {@link ResourceConfig} so that we can handle duplicate
registrations deterministically by not re-registering them again.
connect/runtime/src/main/java/org/apache/kafka/connect/runtime/rest/ConnectRestConfigurable.java