anchor.diff:  
   %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
   
  -not_yet_implemented() ->
  -    skip("not yet implemented").
  +%% not_yet_implemented() ->
  +%%     skip("not yet implemented").
   
   skip(Reason) ->
       throw({skip, Reason}).
  
positive.code: 
  
  api_b_name_and_index() ->
      Names =
          case net:if_names() of
              {ok, N} when is_list(N) andalso (N =/= []) ->
                  N;
              {error, enotsup = Reason} ->
                  i("if_names not supported - skipping"),
                  ?SKIP({if_names, Reason});
              {error, Reason} ->
                  ?FAIL({if_names, Reason})
          end,
      verify_if_names(Names).
  
  verify_if_names([]) ->
      ok;
  
negative.code:     Domain = inet,
      Addr   = which_local_addr(Domain),
      SA     = #{family => Domain, addr => Addr},
      try
          begin
              Hostname =
                  case net:getnameinfo(SA) of
                      {ok, #{host := Name, service := Service} = NameInfo} 
                        when is_list(Name) andalso is_list(Service) ->
                          i("getnameinfo: "
                            "~n   ~p", [NameInfo]),
                          Name;
                      {ok, BadNameInfo} ->
                          ?FAIL({getnameinfo, SA, BadNameInfo});
                      {error, enotsup = ReasonNI} ->
                          i("getnameinfo not supported - skipping"),
                          ?SKIP({getnameinfo, ReasonNI});
                      {error, Reason1} ->
                          ?FAIL({getnameinfo, SA, Reason1})
                  end,
              case net:getaddrinfo(Hostname) of
                  {ok, AddrInfos} when is_list(AddrInfos) ->
                      i("getaddrinfo: "
                        "~n   ~p", [AddrInfos]),
                      verify_addr_info(AddrInfos, Domain);
                  {ok, BadAddrInfo} ->
                      ?FAIL({getaddrinfo, Hostname, BadAddrInfo});
                  {error, enotsup = ReasonAI} ->
                      i("getaddrinfo not supported - skipping"),
                      ?SKIP({getaddrinfo, ReasonAI});
                  {error, Reason2} ->
                      ?FAIL({getaddrinfo, Hostname, Reason2})
              end
          end
      catch
          error : notsup = Reason ->
              i("~w => skipping", [Reason]),
              skip(Reason)
      end.
  
  
  