code: function(computedAlias) {
        var hasAllModels = !_.isUndefined(this.getMapping(computedAlias)),
          models = {};
        _.each(this.__getModelAliases(computedAlias), function(modelAlias) {
          var model = this.getTrackedModel(modelAlias);
          if (model) {
            models[modelAlias] = model;
          } else {
            hasAllModels = false;
          }
        }, this);
        return hasAllModels ? models : undefined;
      }
docs: Returns the models that a currently being tracked that are part of a computed mapping
  If there is a missing model (a model alias is referenced but no model instance is bound to that alias), then it will return undefined.
  @method __getComputedModels
  @param computedAlias {String} the name/alias of the computed mapping
  @return {Object} a map from model name/alias to model instance. If there is a missing model (an model alias is referenced but no model
  instance is bound to that alias), then it will return undefined.
  @private