Man pages matching name dancer2::serializer::mutable in section 3pm:

Dancer2::Serializer::Mutable.3pm.en	debian 10 / libdancer2-perl
Dancer2::Serializer::Mutable.3pm.en	debian 11 / libdancer2-perl
Dancer2::Serializer::Mutable.3pm.en	debian 12 / libdancer2-perl