attr_filter: remove everything, except the avps1,avp2,..

[Jorge Pereira]

Hi,

   Always when I need to remove some avp from a list, I do something like.

update <list> {
    <avp1> !* ANY
    <avp2> !* ANY
    .......
}

But, I would like to know if exist some way to do in an inverted match.
something
like "remove everything, except the avps1,avp2,..."
--
Jorge Pereira