anchor.diff:        do(graph, Args)
     end.
   
  -% rrd "remote" commands
  +%%%%% rrd "remote" commands %%%%
  +
   %% @spec cd(erlang:iodata()) -> ok |  
   %%   { error, Reason } 
   %%  Reason = iolist()
  -%%  Response = iolist()
   %% @doc   ask the rrdtool unix process to change directories
   %% 
   %%    erlrrd:cd("/usr/share/rrd/data").
  
positive.code:       ?_assertExit( { noproc, _ }, ls())
      ]
    ).
  
  start_helper_() -> 
    {ok, Pid} = start_link(), 
  
negative.code:     }
    }.
  
  check_started_(Tag) ->
    wrap_tag_(Tag,
      [
        ?_test(ls()),
        ?_test(pwd()),
        ?_test(ok),
        ?_test(ok)
      ] 
    ).
  
  check_stopped_(Tag) ->
    wrap_tag_(Tag,
      [
  