XML model based content-types do not have a class object and thus neither an interface

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When creating a XML model based content-type no content-type class is created, the base class is plone.dexterity.Container (or plone.dexterity.Item), and not a specific content-type.

Moreover the content-types created like this do not implement the specific interface created to them and dificultes creating an indexer or a any other thing that can be attached to an interface.