my $html = html('<tag>').$raw_characters.html('</tag>');
is($html, $expected_output);
+ok(HTML::String::Value->isa('HTML::String::Value'), 'isa on class ok');
+
+is($@, '', '$@ not set by check');
+
+is do {
+ use HTML::String::Overload;
+ '' . '0'
+}, '0', 'concatenating strings which are false in boolean context';
done_testing;