@Override
    protected Class<?> pojoClass(int id)
    {
        final BaseHS<?> wrapper = id < pojos.size() ? pojos.get(id) : null;
        if (wrapper == null)
        {
            throw new UnknownTypeException("pojo id: " + id +
                    " (Outdated registry)");
        }

        return wrapper.getSchema().typeClass();
    }
Register a {@link Delegate} and assign an id.
<p>
Delegate ids start at 1.
protostuff-runtime-registry/src/main/java/io/protostuff/runtime/ExplicitIdStrategy.java