code: public CompletableFuture<Void> addNewEntriesIfAbsent(String tableName, Map<String, byte[]> toAdd) {
          List<TableEntry<byte[], byte[]>> entries = toAdd.entrySet().stream().map(x ->
                  new TableEntryImpl<>(new TableKeyImpl<>(x.getKey().getBytes(Charsets.UTF_8), KeyVersion.NOT_EXISTS), x.getValue()))
                                                          .collect(Collectors.toList());
          Supplier<String> errorMessage = () -> String.format("addNewEntriesIfAbsent: table: %s", tableName);
          return expectingDataExists(withRetries(() -> segmentHelper.updateTableEntries(tableName, entries, authToken.get(), 
                          RequestTag.NON_EXISTENT_ID), errorMessage)
                  .handle((r, e) -> {
                      if (e != null) {
                          Throwable unwrap = Exceptions.unwrap(e);
                          if (unwrap instanceof StoreException.WriteConflictException) {
                              throw StoreException.create(StoreException.Type.DATA_EXISTS, errorMessage.get());
                          } else {
                              log.debug("add new entries to {} threw exception {} {}", tableName, unwrap.getClass(), unwrap.getMessage());
                              throw new CompletionException(e);
                          }
                      } else {
                          log.trace("entries added to table {}", tableName);
                          return null;
                      }
                  }), null);
      }
docs: Method to add a batch of entries if absent. Table implementation on segment store guarantees that either all or none of
  the entries are added.
  If segment store responds with success, then it is guaranteed that all entries are added to the store.
  However, it is important to note that the segment store could respond with Data Exists even if one of the entries exists.
  In such case, this method will ignore data exist and respond with success for the entire batch. It does not verify
  if all entries existed or one of the entries existed.
  Callers should use this only if they are guaranteed to never create the requested entries outside of the requested batch.
  
  @param tableName table name
  @param toAdd map of keys and values to add.
  @return CompletableFuture which when completed successfully will indicate that all entries have been added successfully.