anchor.diff:  
   %% @hidden
   init(RRDToolCmd) -> 
  -process_flag(trap_exit, true),
  -Port = erlang:open_port({spawn, RRDToolCmd}, [ {line, 10000}, eof, exit_status, stream ] ),
  -{ok, #state{port = Port}}.
  +  process_flag(trap_exit, true),
  +  Port = erlang:open_port(
  +    {spawn, RRDToolCmd},
  +    [ {line, 10000}, eof, exit_status, stream ] 
  +  ),
  +  {ok, #state{port = Port}}.
   
   %%
   %% handle_call
  
positive.code:   receive 
      {'EXIT', Pid, Reason} -> Reason
    after Timeout -> 
      throw({ timeout, Pid, "Pid not responding to EXIT?"})
    end.
  
  start_link_test_() -> 
  
negative.code:     end,
      fun stop_helper_/1,
      { inorder, [ 
        ?_assertExit({port_timeout, _}, do(timeout, [], 1 )),
        ?_assertMatch( {ok, _ }, ls() )
      ]}
    }.
  
  stop_helper_test_() -> 
    { setup, 
      % start fun
      fun() -> 
        F = fun(F) -> 
          receive
            Any -> io:format(user,"~p Hey, got: ~p~n", [ self(), Any ])
          end,
          F(F)
        end,
        spawn(
          fun() -> 
            process_flag(trap_exit, true),
            F(F)
          end
        )
      end,
      % stop fun,
      fun(P) -> exit(P, kill) end,
      % test gen
      fun(P) -> 
        ?_assertThrow({timeout,_}, stop_helper_(P, 1))
      end
    }.
  
  code_change_test() -> 
  