root.getNameManager( ).dropElement( element );
	protected void perform( boolean undo )	{		NameSpace ns = root.getNameSpace( nameSpaceID );		if ( add && !undo || !add && undo )		{			if ( element instanceof ReferenceableElement )			{				ReferenceableElement originalElement = (ReferenceableElement) root						.resolveElement(								element.getName( ),								nameSpaceID,								element										.getPropertyDefn( IDesignElementModel.NAME_PROP ) );				ns.insert( element );				if ( originalElement != null )					updateAllElementReferences( originalElement );			}			else			{				ns.insert( element );			}		}		else		{			ns.remove( element );			if ( element instanceof ReferenceableElement )				updateAllElementReferences( (ReferenceableElement) element );		}	}