code: function(model, options) {
        options = options ? _.extend({}, options) : {};
        if (!(model = this._prepareModel(model, options))) return false;
        if (!options.wait) this.add(model, options);
        var collection = this;
        var success = options.success;
        options.success = function(model, resp) {
          if (options.wait) collection.add(model, options);
          if (success) success(model, resp, options);
        };
  
        var savePromise = model.save(null, options);
        if (savePromise) {
          savePromise.catch(function(err) {});
        }
        return model;
      }
docs: Create a new instance of a model in this collection. Add the model to the collection immediately, unless `wait: true` is passed, in which case we wait for the server to agree.