snippet to chain sync methods to an initial async

gistfile1

        // snippet to chain sync methods to an initial async
        _then: function(f) {
            this._q = this._q || [];
            this._q.push(f);
            return this;
        },
        // continue execution
        _done: function() {
            var m;
            while( (m = this._q.shift()) ) 
                m.call(this);
        }