anchor.diff:  
   %% @doc Replaces do_fun/1 for a version compatible with erlang pre and post 21
   parse_transform(Forms, _Opts) ->
  -    Forms2 = nklib_code:forms_replace_fun(do_try, 1,  make_try_fun(), Forms),
  -    Forms3 = nklib_code:forms_replace_fun(do_config_get, 1,  make_get_fun(), Forms2),
  -    Forms4 = nklib_code:forms_replace_fun(do_config_put, 2,  make_put_fun(), Forms3),
  +    Forms2 = forms_replace_fun(do_try, 1,  make_try_fun(), Forms),
  +    Forms3 = forms_replace_fun(do_config_get, 1,  make_get_fun(), Forms2),
  +    Forms4 = forms_replace_fun(do_config_put, 2,  make_put_fun(), Forms3),
       Forms4.
   
   
  
positive.code:                     nklib_config:put(nklib_trans_comp, Key, Value).
              "
      end,
      {ok, Form} = nklib_code:expression(Exp),
      Form.
  
  
  %% @private
  is_21() ->
      erlang:system_info(otp_release) >= "21".
negative.code:                     nklib_config:get(nklib_trans_comp, Key).
              "
      end,
      forms_expression(Exp).
  
  
  %% @private
  