code: def destroyManager(self, force=False):
          
          if self.getManager(force=force) is not None:
              key = self.getSessionKey()
              del self.session[key]
docs: Delete any YadisServiceManager with this starting URL and
          suffix from the session.
  
          If there is no service manager or the service manager is for a
          different URL, it silently does nothing.
  
          @param force: True if the manager should be deleted regardless
          of whether it's a manager for self.url.