code: public void updateMasters(List<Long> masters, Map<Integer, Long> partitionMasters)
      {
          m_initiatorHSIds.clear();
          m_initiatorHSIds.addAll(masters);
          ((MpTransactionState)getTransactionState()).updateMasters(masters, partitionMasters);
      }
docs: Update the list of partition masters in the event of a failure/promotion.
  Currently only thread-"safe" by virtue of only calling this on
  MpProcedureTasks which are not at the head of the MPI's TransactionTaskQueue.