@Override
    public ClientBuilder connectionMaxIdleSeconds(int connectionMaxIdleSeconds) {
        checkArgument(connectionMaxIdleSeconds < 0
                        || connectionMaxIdleSeconds >= ConnectionPool.IDLE_DETECTION_INTERVAL_SECONDS_MIN,
                "Connection idle detect interval seconds at least "
                        + ConnectionPool.IDLE_DETECTION_INTERVAL_SECONDS_MIN + ".");
        conf.setConnectionMaxIdleSeconds(connectionMaxIdleSeconds);
        return this;
    }
@Test
    public void testConnectionMaxIdleSeconds() throws Exception {
        // test config disabled.
        PulsarClient.builder().connectionMaxIdleSeconds(-1);
        // test config correct
        PulsarClient.builder().connectionMaxIdleSeconds(60);
        // test config not correct.
        try {
            PulsarClient.builder().connectionMaxIdleSeconds(14);
            fail();
        } catch (IllegalArgumentException e){
        }
    }