anchor.diff:      St#st{h=0,hf=0}.
   
   validate_instrs([], MFA, _Offset, #vst{branched=Targets0,labels=Labels0}=Vst) ->
  -    Targets = gb_trees:keys(Targets0),
  -    Labels = gb_sets:to_list(Labels0),
  +    Targets = maps:keys(Targets0),
  +    Labels = cerl_sets:to_list(Labels0),
       case Targets -- Labels of
   	[] -> Vst;
   	Undef ->
  
positive.code: %%  format as used in the compiler and in .S files.
  
  validate(Module, Fs) ->
      Ft = build_function_table(Fs, []),
      validate_0(Module, Fs, Ft).
  
  validate_0(_Module, [], _) -> [];
  
negative.code: 
  init_vst(Arity, Ls1, Ls2, Ft) ->
      Vst0 = init_function_args(Arity - 1, #vst{current=#st{}}),
      Branches = maps:from_list([{L,Vst0#vst.current} || L <- Ls1]),
      Labels = cerl_sets:from_list(Ls1++Ls2),
      Vst0#vst{branched=Branches,
               labels=Labels,
               ft=Ft}.
  