$out .= sprintf '<colgroup span=%d>', 3 * @{$_} for @colmap;
my $huerow = $colmap[0][0]; # first {$_} map { @{$_} } @colmap;
for my $h (grep { $huerow->[$_] } 0 .. $#{$huerow}) {
$out .= sprintf '<colgroup span=%d>', 3 * @{$_} for @colmap;
my $huerow = $colmap[0][0]; # first {$_} map { @{$_} } @colmap;
for my $h (grep { $huerow->[$_] } 0 .. $#{$huerow}) {