anchor.diff:  %%% ------------------------------------------------------------------------
   
   f_msg_header(Spec) ->
  -    {?function, msg_header, 1, msg_header(Spec) ++ [?UNEXPECTED(1)]}.
  +    {?function, msg_header, 1, msg_header(Spec) ++ [?BADARG(1)]}.
   
   msg_header(Spec) ->
       msg_header(get_value(messages, Spec), Spec).
  
positive.code: %%% ------------------------------------------------------------------------
  
  f_avp_header(Spec) ->
      {?function, avp_header, 1, avp_header(Spec) ++ [?UNEXPECTED(1)]}.
  
  avp_header(Spec) ->
      Native = get_value(avp_types, Spec),
  
negative.code:      "%%\n\n").
  
  hrl_header(Name) ->
      header() ++ "-hrl_name('" ++ ?S(Name) ++ ".hrl').\n".
  
  %% avp_info/1
  
  avp_info(Entry) ->  %% {Name, Arity}
      case Entry of
          {{A}} -> {A, 1};
          {A}   -> {A, 1};
          [A]   -> {A, {0,1}};
          {Q,T} ->
              {A,_} = avp_info(T),
              {A, arity(Q)}
  