package HTML::Element;
sub that_is_empty {
my $ct;
return undef unless 1 == @{ ($ct = (shift)->attr('_content')) };
my $lkr;
my $dlv = $ct->[0];
while (ref $dlv eq 'HTML::Element') {
$lkr = $dlv;
($dlv) = @{$dlv->content_array_ref};
}
$lkr=~/\A[[:blank:][:cntrl:]\x{a0}]*\Z/;
}