public void refreshActiveTime(String connectionId) {
        Connection connection = connections.get(connectionId);
        if (connection != null) {
            connection.freshActiveTime();
        }
    }
@Test
    void testRefreshActiveTime() {
        try {
            connectionManager.refreshActiveTime(connectId);
        } catch (Exception e) {
            e.printStackTrace();
            fail(e.getMessage());
        }
    }