anchor.diff:                {wxBitmap:getWidth(Bitmap), wxBitmap:getHeight(Bitmap)},
                 MemoryDC, {0,0}),
       wxMemoryDC:destroy(MemoryDC).
  +
  +refresh(#state{mode=screensaver, bitmap=Bitmap}) ->
  +    DC = wxScreenDC:new(),
  +    redraw(DC, Bitmap),
  +    wxScreenDC:destroy(DC);
  +refresh(#state{mode=interactive, frame=Frame}) ->
  +    wxPanel:refresh(Frame).
  
positive.code: 
  -include("../include/minesweeperl.hrl").
  
  -record(state,
          { frame
          , panel
          , bitmap
          , config
          , board
          , solver_state = flag
          }).
  
  start_link(Rows, Cols, Mines) ->
      Server = wx:new(),
      GameOpts = {Rows, Cols, Mines},
  
negative.code: 
      Panel = wxPanel:new(Frame, []),
      Bitmap = wxBitmap:new(16 * Cols, 16 * Rows),
      Board = create_and_draw_board(Config, Bitmap),
  
      wxPanel:connect(Panel, left_up, [{userData, dummy}]),
      wxPanel:connect(Panel, middle_up, [{userData, dummy}]),
      wxPanel:connect(Panel, right_up, [{userData, dummy}]),
      wxPanel:connect(Panel, paint, [callback]),
      wxPanel:connect(Panel, key_up),
  
      wxFrame:centerOnScreen(Frame),
      wxFrame:show(Frame),
  