code: function(models, copy) {
        _.each(models, function(instance, alias) {
          this.trackModel(alias, instance, copy);
        }, this);
      }
docs: Binds multiple models to their aliases.
  @method trackModels
  @param models {Map from String to Backbone Model instances} A map from alias/name to model to be bound to that alias.
  @param [copy=false] {Boolean} if true, the form model will perform a pull on any mapping using these models.