code: public int loadIndeces(List<RowIndexEntry> rowIndexEntries, int startIndex) {
      int updatedStartIndex = input.loadIndeces(rowIndexEntries, startIndex);
  
      int numIndeces = rowIndexEntries.size();
      indeces = new int[numIndeces + 1];
      int i = 0;
      for (RowIndexEntry rowIndexEntry : rowIndexEntries) {
        indeces[i] = (int) rowIndexEntry.getPositions(updatedStartIndex);
        i++;
      }
      return updatedStartIndex + 1;
    }
docs: Read in the number of bytes consumed at each index entry and store it,
  also call loadIndeces on child stream and return the index of the next
  streams indexes.