code: function(options) {
        options || (options = {});
        if (!this.comparator) throw new Error('Cannot sort a set without a comparator');
        this.models = this.sortBy(this.comparator);
        if (!options.silent) this.trigger('reset', this, options);
        return this;
      }
docs: Force the collection to re-sort itself. You don't need to call this under normal circumstances, as the set will maintain sort order as each item is added.