Are class consts possible?

Is it possible to create class-specific consts i.e., consts that exist
inside a class's namespace?

For example, this does _not_ work:

```

    oo::class create Klass {
        const SPECIAL special

        method say {} { return $SPECIAL }
    }

    set klass [Klass new]
    puts "$Klass::SPECIAL [$klass say]"

```