Adding underscored configs to Neo.Override

I want to be able to add an override including afterSetFoo. That way I can add a real override, which can be supported in the next release or only to my custom project.

Neo.overrides = {
    Neo: {
        component: {
            Base: {
                bar: 2,
                foo_: 1,

                afterSetFoo: function(newValue, oldValue) {
                    let style = this.style;
                    style.color = 'green';
                    this.style = style;
                }
            }
        }
    }
};

export default Neo.overrides;