YUI._setup

    _setup: function(o) {
        var i, Y = this,
            core = [],
            mods = YUI.Env.mods,
            extras = Y.config.core || ['get',
                                        'rls',
                                        'intl-base',
                                        'loader',
                                        'yui-log',
                                        'yui-later',
                                        'yui-throttle'];
 
        for (i = 0; i < extras.length; i++) {
            if (mods[extras[i]]) {
                core.push(extras[i]);
            }
        }
 
        Y._attach(['yui-base']);
        Y._attach(core);
 
    },