### Question:
ServerSessionPoolCenter { public synchronized ServerSessionPool getSickServerSessionPool(DBVendor dbVendor) { DBConnectionInfo dbInfo = getSickDBInfo(dbVendor); PoolId id = new PoolId(dbInfo, true); ServerSessionPool pool = entities.get(id); if (Objects.isNull(pool)) { pool = new ServerSessionPool(dbInfo, true, sickServerSessionFactory); entities.put(id, pool); } else { pool.retain(); } return pool; }  static ServerSessionPoolCenter getInst(); static Map<PoolId, ServerSessionPool> getEntities(); synchronized ServerSessionPool getServerSessionPool(DBConnectionInfo info,
        boolean isAutoCommit); synchronized ServerSessionPool getSickServerSessionPool(DBVendor dbVendor); synchronized ServerSessionPool getBatchOperateServerSessionPool();  }### Answer:
@Test public void testGetSickServerSessionPool() throws Exception { ServerSessionPool fake1 = ServerSessionPoolCenter.getInst().getSickServerSessionPool(DBVendor.MYSQL); ServerSessionPool fake2 = ServerSessionPoolCenter.getInst().getSickServerSessionPool(DBVendor.MYSQL); Assert.assertSame(fake1, fake2); }