docs: function() {
        var retrieveOnceDeferred = $.Deferred();
        var demographicsFetchSuccess = this.get('fetchSuccess');
        if (demographicsFetchSuccess) {
          retrieveOnceDeferred.resolve();
        } else if (demographicsFetchSuccess === false) {
          retrieveOnceDeferred.reject();
        } else {
          this.once('fetched', function() {
            var demographicsFetchSuccess = this.get('fetchSuccess');
            if (demographicsFetchSuccess) {
              retrieveOnceDeferred.resolve();
            } else {
              retrieveOnceDeferred.reject();
            }
          });
        }
        return retrieveOnceDeferred.promise();
      }