### Question:
ManagerPersistHash implements ManagerHash { @Override public boolean isExisted(String field) { try { return jedis.hexists(keyName, field); } catch (Exception e) { logger.error("Exception:{}", LogbackUtil.expection2Str(e)); return Boolean.FALSE; } } ManagerPersistHash(Jedis jedis, String keyName, long maxSpanTime); @Override void addField(String field); @Override void addFields(String... fields); @Override boolean isExisted(String field); @Override void delFields(); @Override List<String> getFields();  }### Answer:
@Test public void testIsExisted() { Jedis jedis = pool.getResource(); jedis.auth(password); try { jedis.hset("keyname", "foo", "bar"); assertEquals("bar", jedis.hget("keyname", "foo")); assertTrue(jedis.hexists("keyname", "foo")); jedis.del("keyname"); } finally { pool.returnResource(jedis); } }