code: private MutateRowsRequest createRetryRequest(List<Integer> indiciesToRetry) {
      MutateRowsRequest.Builder updatedRequest = MutateRowsRequest.newBuilder()
          .setTableName(originalRequest.getTableName());
      mapToOriginalIndex = new int[indiciesToRetry.size()];
      for (int i = 0; i < indiciesToRetry.size(); i++) {
        mapToOriginalIndex[i] = indiciesToRetry.get(i);
        updatedRequest.addEntries(originalRequest.getEntries(indiciesToRetry.get(i)));
      }
      return updatedRequest.build();
    }
docs: Creates a new {@link MutateRowsRequest} that's a subset of the original request that
  corresponds to a set of indices.
  
  @param indiciesToRetry
  @return the new {@link MutateRowsRequest}.