anchor.diff:      FHorizontalGroupByDefs : TmGroupByDefs;
       // Options
       FOptions : TmPivoterOptions;
  +    FEnableSort : boolean;
       // values of keys of group-by sets
       FVerticalValues: TKeyValuesForGroupByDefs;
       FHorizontalValues: TKeyValuesForGroupByDefs;
  
positive.code:   FVerticalKeysIndex := TmKeysIndex.Create(0);
    FHorizontalKeysIndex := TmKeysIndex.Create(0);
    FSummaryDefinitions := TmSummaryDefinitions.Create;
  end;
  
  destructor TmPivoter.Destroy;
  
negative.code:     property SummaryDefinitions : TmSummaryDefinitions read FSummaryDefinitions;
      // options
      property Options : TmPivoterOptions read FOptions write FOptions default pOptionsDef;
      property EnableSort : boolean read FEnableSort write FEnableSort;
  
      // output values
      property VerticalValues: TKeyValuesForGroupByDefs read FVerticalValues; // the collection of all key values for any vertical level
  