anchor.diff:  
   normalize_uriset(_Type, [], Acc1, Acc2) ->
       Acc2++[Acc1].
  +
  +ruri(#uri{}=Uri) ->
  +    Uri#uri{headers=[], ext_opts=[], ext_headers=[]}.
  +
   
   
   
  
positive.code:     [[nksip:uri()]].
  
  normalize_uriset(#uri{}=Uri) ->
      [[Uri]];
  
  normalize_uriset(UriSet) when is_binary(UriSet) ->
      case nksip_parse:uris(UriSet) of
          [] -> [[]];
          UriList -> [UriList]
      end;
  
negative.code: 
  
  normalize_uriset(single, [#uri{}=Uri|R], Acc1, Acc2) -> 
      normalize_uriset(single, R, Acc1++[ruri(Uri)], Acc2);
  
  normalize_uriset(multi, [#uri{}=Uri|R], Acc1, Acc2) -> 
      case Acc1 of
          [] -> normalize_uriset(multi, R, [], Acc2++[[ruri(Uri)]]);
          _ -> normalize_uriset(multi, R, [], Acc2++[Acc1]++[[ruri(Uri)]])
      end;
  
  normalize_uriset(single, [Bin|R], Acc1, Acc2) when is_binary(Bin) -> 
      normalize_uriset(single, R, Acc1++nksip_parse:ruris(Bin), Acc2);
  
  normalize_uriset(multi, [Bin|R], Acc1, Acc2) when is_binary(Bin) -> 
      case Acc1 of
          [] -> normalize_uriset(multi, R, [], Acc2++[nksip_parse:ruris(Bin)]);
          _ -> normalize_uriset(multi, R, [], Acc2++[Acc1]++[nksip_parse:ruris(Bin)])
      end;
  
  normalize_uriset(single, [List|R], Acc1, Acc2) when is_list(List) -> 
      case nksip_lib:is_string(List) of
          true -> normalize_uriset(single, R, Acc1++nksip_parse:ruris(List), Acc2);
          false -> normalize_uriset(multi, [List|R], Acc1, Acc2)
      end;
  
  normalize_uriset(multi, [List|R], Acc1, Acc2) when is_list(List) -> 
      case nksip_lib:is_string(List) of
          true when Acc1=:=[] ->
              normalize_uriset(multi, R, [], Acc2++[nksip_parse:ruris(List)]);
          true ->
              normalize_uriset(multi, R, [], Acc2++[Acc1]++[nksip_parse:ruris(List)]);
          false when Acc1=:=[] ->  
              normalize_uriset(multi, R, [], Acc2++[nksip_parse:ruris(List)]);
          false ->
              normalize_uriset(multi, R, [], Acc2++[Acc1]++[nksip_parse:ruris(List)])
      end;
  
  normalize_uriset(Type, [_|R], Acc1, Acc2) ->
  