public interface IntersectableAssertion
Assertions that need special consideration to implement
the intersection algorithms should implement this interface.
If an assertion does not implement this interface, the
intersection algorithm will just check the qname of the
assertion as well as the contained policy if the assertion
implements the PolicyContainingAssertion interface. This
is adequate for most use cases and per spec, but this
interface allows an assertion to possibly consider special
attributes or other details to determine the behavior
for the intersection.