DELPHI - How to go through all rows in dataset with bookmark

Bookmarks store your position in dataset and  after action you can return back to original record.

var
  iCount : integer;
  pBookmark : TBookmark;
  pDataSetSource : TDataSet;
begin
  ...
  Screen.Cursor := crHourGlass;
  iCount := 1;
  pBookmark := pDatasetSource.GetBookmark;
  pDatasetSource.DisableControls;
  try

    pDatasetSource.First;
    while not pDatasetSource.Eof do
      begin
        try

          { action with record }

        finally
          inc( iCount );
          pDatasetSource.Next;
        end;

      end;
  finally
    pDatasetSource.GotoBookmark( pBookmark );
    pDatasetSource.EnableControls;

    Screen.Cursor := crDefault;
  end;