anchor.diff:  
       ?line {'EXIT', {badarg, _}} = 
           (catch family_to_digraph(set([a]))),
  -    ?line {'EXIT', {badarg, [{sofs,family_to_digraph,[_,_],_}|_]}} =
  -        (catch family_to_digraph(set([a]), [foo])),
  -    ?line {'EXIT', {badarg, [{sofs,family_to_digraph,[_,_],_}|_]}} =
  -        (catch family_to_digraph(F, [foo])),
  -    ?line {'EXIT', {cyclic, [{sofs,family_to_digraph,[_,_],_}|_]}} =
  -        (catch family_to_digraph(family([{a,[a]}]),[acyclic])),
  +    digraph_fail(badarg, catch family_to_digraph(set([a]), [foo])),
  +    digraph_fail(badarg, catch family_to_digraph(F, [foo])),
  +    digraph_fail(cyclic, catch family_to_digraph(family([{a,[a]}]),[acyclic])),
   
       ?line G1 = family_to_digraph(E),
       ?line {'EXIT', {badarg, _}} = (catch digraph_to_family(G1, foo)),
  
positive.code:     ?line true = T0 == ets:all(),
      ok.
  
  constant_function(suite) -> [];
  constant_function(doc) -> [""];
  constant_function(Conf) when is_list(Conf) ->
  
negative.code:                difference(S, RR)),
  
      %% The function external:foo/1 is undefined.
      case test_server:is_native(sofs) of
  	true ->
  	    %% Create an export entry for external:foo/1 to work
  	    %% around a bug in the native code. If there is no
  	    %% export entry, the exception will be
  	    %% {badfun,{external,foo}}. Remove in R16 when tuple
  	    %% funs are removed.
  	    (catch external:foo([]));
  	false ->
  	    ok
      end,
      ?line {'EXIT', {undef, _}} =    
   	(catch projection({external,foo}, set([a,b,c]))),
      ok.
  