anchor.diff:  
   procedure TAddCommand.Execute;
   begin
  -  Writeln('>> TAddComand.Execute');
  +  DebugLn('>> TAddComand.Execute');
     FMemo.Lines.Add('Hello ' + IntToStr(Random(500)));
     FMemo.Invalidate;
   end;
  
positive.code: 
  procedure TExitCommand.Execute;
  begin
    Writeln('>> TExitComand.Execute');
    fpgApplication.Terminated := True;
  end;
  
  
negative.code: 
  { TNullInterfacedObject }
  
  function TNullInterfacedObject.QueryInterface(constref IID: TGUID; out Obj): longint; {$IFNDEF WINDOWS}cdecl{$ELSE}stdcall{$ENDIF};
  begin
    if GetInterface(IID, Obj) then
      Result := 0
  