anchor.diff:              {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})
  
positive.code:     lists:flatten(io_lib:format(F, A)).
  
  
  %% i(F) ->
  %%     i(F, []).
  
  i(F, A) ->
      FStr = f("[~s] " ++ F, [formated_timestamp()|A]),
  
negative.code:         {ok, BadIndex} ->
              ?FAIL({if_name2index, Name, Index, BadIndex});
          {error, enotsup = Reason_N2I1} ->
              i("if_name2index not supported - skipping"),
              ?SKIP({if_name2index, Reason_N2I1});
          {error, Reason_N2I2} ->
              ?FAIL({if_name2index, Name, Reason_N2I2})
  