docs: private StmtTargetTableScan addSimplifiedSubqueryToStmtCache(
              StmtSubqueryScan subqueryScan, StmtTargetTableScan tableScan) {
          String tableAlias = subqueryScan.getTableAlias();
          assert(tableAlias != null);
          // It is guaranteed by the canSimplifySubquery that there is
          // one and only one TABLE in the subquery's FROM clause.
          Table promotedTable = tableScan.getTargetTable();
          StmtTargetTableScan promotedScan =
                  new StmtTargetTableScan(promotedTable, tableAlias, m_stmtId);
          // Keep the original subquery scan to be able to tie the parent
          // statement column/table names and aliases to the table's.
          promotedScan.setOriginalSubqueryScan(subqueryScan);
          // Replace the subquery scan with the table scan
          StmtTableScan prior = m_tableAliasMap.put(tableAlias, promotedScan);
          assert(prior == subqueryScan);
          m_tableList.add(promotedTable);
          return promotedScan;
      }