Session.addFeatureByType

If feature_type is the type of a class that implements soup.session_feature.SessionFeature, 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 soup.session_feature.SessionFeature type, this gives each existing feature on session the chance to accept feature_type as a "subfeature". This can be used to add new soup.auth.Auth types, for instance.

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