code: function() {
          var editDataSource = this.getProperty( 'editDataSource' );
          var destinationDataSource = this.getProperty( 'destinationDataSource' );
          var destinationProperty = this.getProperty( 'destinationProperty' ) || '';
  
          if( !destinationDataSource ) {
              return;
          }
  
          if( this._isObjectDataSource( editDataSource ) ) {
              var newItem = editDataSource.getSelectedItem();
  
              if( this._isRootElementPath( destinationProperty ) ) {
                  destinationDataSource._includeItemToModifiedSet( newItem );
                  destinationDataSource.saveItem( newItem, function() {
                      destinationDataSource.updateItems();
                  } );
              } else {
                  var items = destinationDataSource.getProperty( destinationProperty ) || [];
  
                  items = _.clone( items );
                  items.push( newItem );
  
                  destinationDataSource.setProperty( destinationProperty, items );
              }
          } else {
              destinationDataSource.updateItems();
          }
      }
docs: Save item in destination data source