code: function (model) {
              if (!this.ngModel) {
                  return; // A kb-item can't be selected without a ng-model on the container element.
              }
              if (this.multiple) {
                  if (this.isSelected(model) === false) {
                      this.selected.push(model);
                      this.ngModel.$setViewValue(this.selected);
                  }
              } else {
                  this.selected[0] = model;
                  this.ngModel.$setViewValue(model);
              }
          }
docs: Select the given model.
  Or in multiselect mode, add the given model to the selection.
  
  @param {*} model