@Override
  public void abort_txns(AbortTxnsRequest rqst) throws TException {
    getTxnHandler().abortTxns(rqst);
    if (listeners != null && !listeners.isEmpty()) {
      for (Long txnId : rqst.getTxn_ids()) {
        // See above abort_txn() note about not adding dbsUpdated.
        MetaStoreListenerNotifier.notifyEvent(listeners, EventType.ABORT_TXN,
            new AbortTxnEvent(txnId, this));
      }
    }
  }
Check if newRole is in parent hierarchy of curRole
@param newRole
@param curRole
@return true if newRole is curRole or present in its hierarchy
@throws MetaException
standalone-metastore/metastore-server/src/main/java/org/apache/hadoop/hive/metastore/HMSHandler.java