public void removeType(URI typeId)
    {
        // We may have different version of the class being loaded by
        // different class loaders. We need to make sure all version are
        // removed from the cache since the type is no longer in HGDB.
        Set<Class<?>> S = new HashSet<Class<?>>();
        String clname = uriToClassName(typeId);
        for (Class<?> cl : classToAtomType.keySet())
            if (cl.getName().equals(clname))
                S.add(cl);
        for (Class<?> cl : S)
            classToAtomType.remove(cl);
    }