if (defined($clock_info)) {
$pos->{'white_clock'} //= $clock_info->{'white_clock'};
$pos->{'black_clock'} //= $clock_info->{'black_clock'};
if (defined($clock_info)) {
$pos->{'white_clock'} //= $clock_info->{'white_clock'};
$pos->{'black_clock'} //= $clock_info->{'black_clock'};