docs: static protected void resolveUsingExpressions(List<VoltXMLElement> elements, RangeVariable[] rvs)
              throws org.hsqldb_voltpatches.HSQLInterface.HSQLParseException {
  
          for (VoltXMLElement element : elements) {
              String table = null;
              String tableAlias = null;
              boolean isFullJoin = false;
              assert(element.hasValue("optype", "operator_case_when"));
              String column = element.attributes.get("column");
              for (RangeVariable rv : rvs) {
                  if (!rv.getTable().columnList.containsKey(column)) {
                      // The column is not from this table. Skip it
                      continue;
                  }
  
                  // If there is an OUTER join we need to pick the outer table
                  if (rv.isRightJoin == true) {
                      if (rv.isLeftJoin == true) {
                          // this is a full join. No need to do anything
                          isFullJoin = true;
                      } else {
                          // this is the outer table. no need to search
                          // further.
                          table = rv.getTable().getName().name;
                          if (rv.tableAlias != null) {
                              tableAlias = rv.tableAlias.name;
                          } else {
                              tableAlias = null;
                          }
                      }
                      break;
                  } else if (rv.isLeftJoin == false) {
                      // it's the inner join. we found the table but still need to iterate
                      // just in case there is an outer table we haven't seen yet.
                      table = rv.getTable().getName().name;
                      if (rv.tableAlias != null) {
                          tableAlias = rv.tableAlias.name;
                      } else {
                          tableAlias = null;
                      }
                  }
              }
              if (isFullJoin) {
                  continue;
              }
              if (table != null) {
                  collapseCoalesceExpression(element, table, tableAlias);
              }
          }
      }