code: void sortByTveIndex(int fromIndex, int toIndex) {
          Collections.sort(m_columns.subList(fromIndex, toIndex), TVE_IDX_COMPARE);
      }
docs: Sort a sub-range of the schema columns by TVE index.  All elements
  must be TupleValueExpressions.  Modification is made in-place.
  @param fromIndex   lower bound of range to be sorted, inclusive
  @param toIndex     upper bound of range to be sorted, exclusive