@Before
  public void setUp() throws Exception {
    conf = MetastoreConf.newMetastoreConf();
    underTest = new AcidTxnCleanerService();
    underTest.setConf(conf);
    txnHandler = TxnUtils.getTxnStore(conf);
    txnHandler.setOpenTxnTimeOutMillis(100);
    TestTxnDbUtil.prepDb(conf);
  }
Testing whether AcidTxnCleanerService removes the correct records
from the TXNS table (via TxnStore).
standalone-metastore/metastore-server/src/test/java/org/apache/hadoop/hive/metastore/txn/TestAcidTxnCleanerService.java