Man pages matching name perlbal::xs::httpheaders in section 3pm:

Perlbal::XS::HTTPHeaders.3pm.en	debian 10 / libperlbal-xs-httpheaders-perl
Perlbal::XS::HTTPHeaders.3pm.en	debian 11 / libperlbal-xs-httpheaders-perl
Perlbal::XS::HTTPHeaders.3pm.en	debian 12 / libperlbal-xs-httpheaders-perl