anchor.diff:    PeerSubset)
     when Id >= PeerSubset#peer_subset.lowest_stream_id,
          Id < PeerSubset#peer_subset.next_available_stream_id ->
  -    OldStream = lists:keyfind(Id, 2, PeerSubset#peer_subset.active),
  +    OldStream = get_from_subset(Id, PeerSubset),
       OldType = type(OldStream),
       ActiveDiff =
           case OldType of
  
positive.code:               lowest_stream_id=PeerSubset#peer_subset.next_available_stream_id,
                active_count=0,
                active=[]
                };
          [NewLowestStream|_] ->
              NewLowest = stream_id(NewLowestStream),
              PeerSubset#peer_subset{
  
negative.code:   PeerSubset)
    when Id >= PeerSubset#peer_subset.lowest_stream_id,
         Id < PeerSubset#peer_subset.next_available_stream_id ->
      OldStream = get_from_subset(Id, PeerSubset),
      OldType = type(OldStream),
      ActiveDiff =
          case OldType of
  