code: function(options) {
        options || (options = {});
        if (!this.comparator) throw new Error('Cannot sort a set without a comparator');
        var boundComparator = _.bind(this.comparator, this);
        if (this.comparator.length == 1) {
          this.models = this.sortBy(boundComparator);
        } else {
          this.models.sort(boundComparator);
        }
        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.