docs: private void expireSessions(long timestamp) {
      // Iterate through registered sessions.
      for (RaftSession session : sessions.getSessions(primitiveId)) {
        if (session.isTimedOut(timestamp)) {
          log.debug("Session expired in {} milliseconds: {}", timestamp - session.getLastUpdated(), session);
          session = sessions.removeSession(session.sessionId());
          if (session != null) {
            session.expire();
            service.expire(session.sessionId());
          }
        }
      }
    }