/// <exception cref="System.IO.IOException"/>
public override bool SeekToNewSource(long targetPos)
{
long sumsPos = GetChecksumFilePos(targetPos);
fs.ReportChecksumFailure(file, datas, targetPos, sums, sumsPos);
bool newDataSource = datas.SeekToNewSource(targetPos);
return(sums.SeekToNewSource(sumsPos) || newDataSource);
}