docs: private void applyCloseSession(Indexed<CloseSessionEntry> entry) {
      RaftSession session = raft.getSessions().getSession(entry.entry().session());
  
      // If the server session is null, the session either never existed or already expired.
      if (session == null) {
        throw new RaftException.UnknownSession("Unknown session: " + entry.entry().session());
      }
  
      RaftServiceContext service = session.getService();
      service.closeSession(entry.index(), entry.entry().timestamp(), session, entry.entry().expired());
  
      // If this is a delete, unregister the service.
      if (entry.entry().delete()) {
        raft.getServices().unregisterService(service);
        service.close();
      }
    }