Avi's "Singletons" package might be what you're looking for..

On 9/18/07, Brad Fuller <bradallenfuller at yahoo.com> wrote:
> Is there a way to override an instance method w/o subclassing?
> For instance, class Morph has a method that returns true, but I want the
> that
> method to return false when instancing some types of Morphs and others not.
> (there is no setter/getter for this method.) Is there a way to do that w/o
> adding a setter/getter to Morph or subclassing the different Morphs?
>
>