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