anchor.diff:      function GetCount(): Integer;
       function GetSavePoint(aTick: Cardinal): TKMSavePoint;
       function GetStream(aTick: Cardinal): TKMemoryStream;
  +    function GetLastTick: Cardinal;
  +    procedure SetLastTick(const aLastTick: Cardinal);
     public
       constructor Create();
       destructor Destroy; override;
   
  -    property LastTick: Cardinal read fLastTick write fLastTick;
  +    property LastTick: Cardinal read GetLastTick write SetLastTick;
       procedure Clear;
   
       procedure Lock;
  
positive.code:   key: Cardinal;
  begin
    Result := 0;
  
    Lock;
    try
  
negative.code: function TKMSavePointCollection.GetSavePoint(aTick: Cardinal): TKMSavePoint;
  begin
    Result := nil;
    if Self = nil then Exit;
  
    Lock;
    try
      if fSavePoints.ContainsKey(aTick) then
  