docs: @Override
      protected ConsistentKeyLockStatus writeSingleLock(KeyColumn lockID, StoreTransaction txh) throws Throwable {
  
          final StaticBuffer lockKey = serializer.toLockKey(lockID.getKey(), lockID.getColumn());
          StaticBuffer oldLockCol = null;
  
          for (int i = 0; i < lockRetryCount; i++) {
              WriteResult wr = tryWriteLockOnce(lockKey, oldLockCol, txh);
              if (wr.isSuccessful() && wr.getDuration().compareTo(lockWait) <= 0) {
                  final Instant writeInstant = wr.getWriteTimestamp();
                  final Instant expireInstant = writeInstant.plus(lockExpire);
                  return new ConsistentKeyLockStatus(writeInstant, expireInstant);
              }
              oldLockCol = wr.getLockCol();
              handleMutationFailure(lockID, lockKey, wr, txh);
          }
          tryDeleteLockOnce(lockKey, oldLockCol, txh);
          // TODO log exception or successful too-slow write here
          throw new TemporaryBackendException("Lock write retry count exceeded");
      }