docs: function CheckboxFieldDirective($log, fieldHelper) {
              this.require = '^formFor';
              this.restrict = 'EA';
              this.templateUrl = function ($element, $attributes) {
                  return $attributes['template'] || 'form-for/templates/checkbox-field.html';
              };
              this.scope = {
                  attribute: '@',
                  disable: '=',
                  help: '@?',
                  changed: '&?'
              };
              $log_ = $log;
              fieldHelper_ = fieldHelper;
          }