Man pages matching name go::handlers::obo_godb_flat in section 3pm:

GO::Handlers::obo_godb_flat.3pm.en	debian 10 / libgo-perl
GO::Handlers::obo_godb_flat.3pm.en	debian 11 / libgo-perl
GO::Handlers::obo_godb_flat.3pm.en	debian 12 / libgo-perl