""" Illustrates various methods of associating multiple types of parents with a particular child object. The examples all use the declarative extension along with declarative mixins. Each one presents the identical use case at the end - two classes, ``Customer`` and ``Supplier``, both subclassing the ``HasAddresses`` mixin, which ensures that the parent class is provided with an ``addresses`` collection which contains ``Address`` objects. The :viewsource:`.discriminator_on_association` and :viewsource:`.generic_fk` scripts are modernized versions of recipes presented in the 2007 blog post `Polymorphic Associations with SQLAlchemy <http://techspot.zzzeek.org/2007/05/29/polymorphic-associations-with-sqlalchemy/>`_. .. autosource:: """ # noqa