manageId( content, false );
module.manageId( content, false, false );
	protected void perform( boolean undo )	{		ContainerSlot slot = container.getSlot( slotID );		if ( add && !undo || !add && undo )		{			slot.insert( content, oldPosn );			// Cache the inverse relationship.			content.setContainer( container, slotID );			// Add the item to the element ID map if we are using			// element IDs.			if ( content.getRoot( ) != null )				manageId( content, true );		}		else		{			slot.remove( content );						// Remove the element from the ID map if we are using			// IDs.			if ( content.getRoot( ) != null )				manageId( content, false );			// Clear the inverse relationship.			content.setContainer( null, DesignElement.NO_SLOT );					}	}