anchor.diff:  fold_ast(H, Acc) when is_list(H), length(H) > 1 ->
       M = fold_list(fun (A) -> fold_ast(A, []) end, H, []),
       fold_ast([], ["[", M, "]" | Acc]).
  +%% if binary, nothing to do here
  +fold_ast(Binary) when is_binary(Binary) ->
  +    Binary;
  +%% default
   fold_ast(Ast) ->
       list_to_binary(fold_ast(Ast, [])).
   
  
positive.code: json_mutation(Ast, {N, _NT}, 4) ->
      {Res, _, _} = json_insert(Ast, N),
      {[{json_insert, 1}], Res, 1};
  json_mutation(Ast, {N, _NT}, _R) when N > 0 ->  %% Prob = 25% for inner mutation 
      Muta = erlamsa_mutations:mutators_mutator(erlamsa_mutations:inner_mutations()),
      {Res, Meta} = walk2acc(Ast,
  
negative.code:     {Meta, binary_to_list(hd(NewLstBin))}.
  
  json_mutation(Ast, {N, NT}) ->
      json_mutation(Ast, {N, NT}, erlamsa_rnd:rand(8)).
  
  json_mutation(Ast, {N, _NT}, 0) ->
      {Res, _, _} = json_swap(Ast, N),
  