docs: private void fillUpAggResultColumns () {
          for (ParsedColInfo col : m_displayColumns) {
              if (m_aggResultColumns.contains(col)) {
                  continue;
              }
  
              if (col.m_expression instanceof TupleValueExpression) {
                  m_aggResultColumns.add(col);
              }
              else {
                  // Col must be complex expression (like: TVE + 1, TVE + AGG)
                  List<TupleValueExpression> tveList = new ArrayList<>();
                  findAllTVEs(col.m_expression, tveList);
                  insertTVEsToAggResultColumns(tveList);
              }
          }
      }