private List<Long> openTxnImpl(final String user, final int numTxns) throws TException {
    return conn.getMSC().openTxns(user, numTxns).getTxn_ids();
  }
Represents a batch of transactions acquired from MetaStore.

@param conn - hive streaming connection
@throws StreamingException if failed to create new RecordUpdater for batch
streaming/src/java/org/apache/hive/streaming/TransactionBatch.java