anchor.diff:          maybe_gen_rpc_callback_specs(Context, FuncList),
           gen_embedded_piqi(ErlMod),
           gen_get_piqi(ErlMod),
  -        gen_server_stubs(Context, FuncList, Mod, ErlMod)
  +        gen_func_io_helpers(Context, FuncList, ErlMod),
  +        gen_server_stubs(FuncList, Mod)
       ]),
       ok = piqic:write_file(Filename, Code).
   
  
positive.code: gen_default_impl(Context, F) ->
      Piqi = Context#context.piqi,
      ErlMod = Piqi#piqi.erlang_module,
  
      Input =
          case F#func.input of
              'undefined' -> "'undefined'";
  
negative.code:             'undefined' -> % the function doesn't produce errors
                  [];
              _ ->
                  ErrEncodeFun = ["fun gen_", ErlName, "_error/1"],
                  [[
  "                {error, Error} ->\n"
  "                    piqi_rpc_runtime:encode_error(?MODULE, ", ErrEncodeFun, ",\n",
  "                       <<\"", ScopedName, "-error\">>, _OutputFormat, Error, Options)"
                  ]]
          end,
  
  