question: private boolean removeExpiredAttachmentPoints ( List < AttachmentPoint > apList ) { List < AttachmentPoint > expiredAPs = new ArrayList < AttachmentPoint > ( ) ; if ( apList == null ) return false ; for ( AttachmentPoint ap : apList ) { if ( ap . getLastSeen ( ) + AttachmentPoint . INACTIVITY_INTERVAL < System . currentTimeMillis ( ) ) expiredAPs . add ( ap ) ; } if ( expiredAPs . size ( ) > 0 ) { apList . removeAll ( expiredAPs ) ; return true ; } else return false ; }
target:  Remove all attachment points that are older than INACTIVITY_INTERVAL from the list.