stack.commit( );
else { stack.rollbackAll( ); }
	public void run( )	{		// create a CommandStack object here to support UNDO/REDO command for		// multi-insert action.		CommandStack stack = SessionHandleAdapter.getInstance( )				.getActivityStack( );		stack.startTrans( STACK_MSG_INSERT_GROUP );		ArrayList parts = getListEditParts( );		// Performs insertGroup() for each listEditPart ( or list element )		// contained in the arrayList, which are currently selected objects.		for ( int i = 0; i < parts.size( ); i++ )		{			( (ListEditPart) parts.get( i ) ).insertGroup( );		}		stack.commit( );	}