code: def explicitLogout(self, session):
          
          guard.SessionWrapper.explicitLogout(self, session)
          self.removeSessionWithKey(session.uid)
docs: Handle a user-requested logout.
  
          Here we override guard's behaviour for the logout action to delete the
          persistent session.  In this case the user has explicitly requested a
          logout, so the persistent session must be deleted to require the user
          to log in on the next request.
  
          @type session: L{nevow.guard.GuardSession}
          @param session: The session of the user logging out.