code: public CompletableFuture<TxnStatus> abortTxn(final String scope,
                                                   final String stream,
                                                   final UUID txId,
                                                   final Version version,
                                                   final OperationContext contextOpt) {
          final OperationContext context = getNonNullOperationContext(scope, stream, contextOpt);
          return withRetriesAsync(() -> sealTxnBody(hostId, scope, stream, false, txId, version, context),
                  RETRYABLE_PREDICATE, 3, executor);
      }
docs: Abort transaction.
  
  @param scope  stream scope.
  @param stream stream name.
  @param txId   transaction id.
  @param version Expected version of the transaction record in the store.
  @param contextOpt       operational context
  @return true/false.