anchor.diff:    protected
       procedure Grow; overload; virtual; abstract;
       procedure Grow(N: Integer); overload; virtual; abstract;
  -    function Get(Index: Integer): Variant; virtual; abstract;
  -    procedure Put(Index: Integer; const Value: Variant); virtual; abstract;
       function GetCapacity: Integer; virtual; abstract;
       function GetCount: Integer; virtual; abstract;
       procedure SetCapacity(NewCapacity: Integer); virtual; abstract;
  
positive.code:     function Delete(Index: Integer): Variant; virtual; abstract;
      procedure DeleteRange(Index, Count: Integer); virtual; abstract;
      procedure Exchange(Index1, Index2: Integer); virtual; abstract;
      function GetEnumerator: IListEnumerator; virtual;
      function IndexOf(const Value: Variant): Integer; virtual; abstract;
      function LastIndexOf(const Value: Variant): Integer; virtual; abstract;
  
negative.code:     function Delete(Index: Integer): Variant; override;
      procedure DeleteRange(Index, ACount: Integer); override;
      procedure Exchange(Index1, Index2: Integer); override;
      function Get(Index: Integer): Variant; override;
      procedure Put(Index: Integer; const Value: Variant); override;
      function IndexOf(const Value: Variant): Integer; override;
      function LastIndexOf(const Value: Variant): Integer; override;
      procedure Insert(Index: Integer; const Value: Variant); override;
  