anchor.diff:      { ok, Id }.
   
   mocked_lurch_device_stop( Id ) ->
  -    whereis( lurch_devman ) ! { stop, shutdown, Id },
  -    ok.
  +    NumCalls = meck:num_calls( lurch_device, stop, [ Id ] ),
  +    if
  +        NumCalls > 0 -> ok;
  +        true ->
  +            whereis( lurch_devman ) ! { stop, shutdown, Id },
  +            ok
  +    end.
   
   -endif. % TEST
  
positive.code:     Id = make_ref(),
      Id2 = make_ref(),
      Device = #device{ id = Id, state = running,
                        stopped_by = { make_ref(), self() } },
      Devices = orddict:store( Id, Device, orddict:new() ),
      S0 = #state{ devices = Devices },
  
  
negative.code:     NewState = State#state{ devices = Devices },
      { noreply, NewState };
  
  
  handle_call( { stop_device, DeviceId }, From, State ) ->
      handle_stop_device_request( DeviceId, From, State );
  
  
  handle_call( list_devices, _From, State ) ->
  