@BeforeClass
  public void setup() {
    System.setProperty(PropertyConstants.PROPERTY_REDIS_ADDRESS, REDIS_IP_PORT);
    System.setProperty(PropertyConstants.PROPERTY_REDIS_TIMEOUT, String.valueOf(REDIS_TIMEOUT));
    System.setProperty(PropertyConstants.PROPERTY_ZOOKEEPER_ADDRESS, ZK_ADDR);
    System.setProperty(PropertyConstants.PROPERTY_ZOOKEEPER_RULE_PATH, ZK_PATH);

    redisConfig.setAddress(REDIS_IP_PORT);
    redisConfig.setTimeout(REDIS_TIMEOUT);
    zookeeperConfig.setAddress(ZK_ADDR);
    zookeeperConfig.setPath(ZK_PATH);
  }
exceptions:

case 1: zookeeper access failed/timeout.

case 2: zookeeper does not have the node path.

case 3: config file not existed.

case 4: config invalid.

case 5: redis connection failed.

case 6: redis access timeout.
src/test/java/com/eudemon/ratelimiter/integration/UrlRateLimiterIT.java