Simple Schema multiple types for field

Hello Everybody!
I was wondering if its possible to have multiple types for a single field in simple schema, something like this:

new SimpleSchema({
    param: {
        type: [ String, Number ]
    }
});

@aldeed
Thanks a lot!

I thing it has to be a string. If you store a number aybe you could try turn the string back into a number?

Is not possible then?