This is actually part of the logic needed to get the final assertion generated.  If you run locally, the last sign in will generate an assertion, resulting in multiple assertions. However, it's difficult to know if we have 1 or more assertions without an event that occurs after all assertions have been generated.  Thus, this logout_session is a work around for that.   We've already abstracted away most all detail from the actual test and other tests require this logic for getting the correct assertion.  This helps us avoid repeating code.