I know how to do plugins, but how do I do nested options like:

var defaults = {
    spacing:10,
    shorten_to:50,
    from_start:0,
    from_end:2,
    classes: {
        test:'testing'
    }
};

i know that isn't right, i just dont know how to write the proper syntax when I want to do something like this:

$('#breadcrumbs').breadcrumbs({classes{test:'new_example'},spacing:12})

other suggestions are welcome, im in need of the ability to custom class names and there are 7, so rather than making something like test_class, example_class, etc id like it cleaner and neater like the example above.