Session.addFeatureByType

If feature_type is the type of a class that implements ifaceSessionFeature, this creates a new feature of that type and adds it to session as with [soup.session.Session.addFeature]. You can use this when you don't need to customize the new feature in any way. Adding multiple features of the same feature_type is not allowed.

If feature_type is not a ifaceSessionFeature type, this gives each existing feature on session the chance to accept feature_type as a "subfeature". This can be used to add new classAuth types, for instance.

See the main #SoupSession documentation for information on what features are present in sessions by default.