code: function (oldItem, newItem) {
          var ctrlElm, items = this.items(), i = items.length;
  
          // Replace the item in collection
          while (i--) {
            if (items[i] === oldItem) {
              items[i] = newItem;
              break;
            }
          }
  
          if (i >= 0) {
            // Remove new item from DOM
            ctrlElm = newItem.getEl();
            if (ctrlElm) {
              ctrlElm.parentNode.removeChild(ctrlElm);
            }
  
            // Remove old item from DOM
            ctrlElm = oldItem.getEl();
            if (ctrlElm) {
              ctrlElm.parentNode.removeChild(ctrlElm);
            }
          }
  
          // Adopt the item
          newItem.parent(this);
        }
docs: Replaces the specified child control with a new control.
  
  @method replace
  @param {tinymce.ui.Control} oldItem Old item to be replaced.
  @param {tinymce.ui.Control} newItem New item to be inserted.