anchor.diff:  get_localaddr([Localhost|Ls]) ->
       case inet:getaddr(Localhost, inet6) of
          {ok, LocalAddr} ->
  -           io:format("~s ~p~n", [Localhost, LocalAddr]),
  +           p("~s ~p", [Localhost, LocalAddr]),
              {ok, LocalAddr};
          _ ->
              get_localaddr(Ls)
  
positive.code: 		filelib:wildcard(
  		  "/tmp/" ?MODULE_STRING "_" ++ os:getpid() ++ "_*")],
      ok.
  
negative.code: %%% implicit inet6 option to api functions
  
  t_implicit_inet6(Config) when is_list(Config) ->
      try do_t_implicit_inet6(Config)
      catch
          throw:{skip, _} = SKIP ->
              SKIP
      end.
  
  do_t_implicit_inet6(_Config) ->
      p("try get hostname"),
      Host = ok(inet:gethostname()),
      p("try get address for host ~p", [Host]),
      case inet:getaddr(Host, inet6) of
  	{ok, Addr} ->
              p("address: ~p", [Addr]),
  	    t_implicit_inet6(Host, Addr);
  	{error, Reason} ->
  	    {skip,
  	     "Can not look up IPv6 address: "
  	     ++atom_to_list(Reason)}
  