docs: function ModalNavigationInterceptor(spec) {
      // ---------------------------------------------- input arguments processing
  
      if (!ariaUtilsType.isObject(spec)) {
          spec = {getReferenceElement: spec};
      }
  
      // -------------------------------------------------------------- processing
  
      var finalSpec = ariaUtilsObject.assign({}, spec, {
          origin: 'popup',
  
          focusTraps: [
              // before
              {
                  direction: 'backward',
                  insert: insertBefore
              },
              // after
              {
                  direction: 'forward',
                  insert: insertAfter
              }
          ]
      });
  
      // ------------------------------------------------------------------ return
  
      return NavigationInterceptor(finalSpec);
  }