### Question:
JedisFactory { public static final Jedis getJedisDB() { if ( jedisDB == null ) { initJedis(); } return jedisDB; }  static void initJedis(); static Jedis createJedis(String host, int port); static void disableJedis(); static final Jedis getJedis(); static final Jedis getJedisDB();  }### Answer:
@Test public void testPersistent() throws Exception { final Jedis jedisDB = JedisFactory.getJedisDB(); jedisDB.set("testthread", "helloworld"); assertEquals("helloworld", jedisDB.get("testthread")); }