Did anyone ever succesfully extend the MultiAttachmentsField controller?

Hi, 

I was wondering if anyone succesfully extended the MultiAttachmentsField Controller? I need to make a small change to the format function so the url that is generated is a bit different for some reason as soon as I make a new file custom/modules/Notes/clients/base/fields/multi-attachments/multi-attachments.js and add the following content the field seems to be broken?

({
    extendsFrom: 'BaseMultiAttachmentsField',

    format: function (value) {
        return this.super("format",value);
    }
})

even if I add the contructor to it with this.super('initialize',[options]) in it, it doesnt seem to be working. Any idea's on how to extend it correctly?