docs: private static void validateMigrateStmt(String sql, VoltXMLElement xmlSQL, Database db) {
          final Map<String, String> attributes = xmlSQL.attributes;
          assert attributes.size() == 1;
          final Table targetTable = db.getTables().get(attributes.get("table"));
          assert targetTable != null;
          final CatalogMap<TimeToLive> ttls = targetTable.getTimetolive();
          if (ttls.isEmpty()) {
              throw new PlanningErrorException(String.format(
                      "%s: Cannot migrate from table %s because it does not have a TTL column",
                      sql, targetTable.getTypeName()));
          } else {
              final Column ttl = ttls.iterator().next().getTtlcolumn();
              final TupleValueExpression columnExpression = new TupleValueExpression(
                      targetTable.getTypeName(), ttl.getName(), ttl.getIndex());
              if (! ExpressionUtil.collectTerminals(
                      ExpressionUtil.from(db,
                              VoltXMLElementHelper.getFirstChild(
                                      VoltXMLElementHelper.getFirstChild(xmlSQL, "condition"),
                                      "operation")))
                      .contains(columnExpression)) {
                  throw new PlanningErrorException(String.format(
                          "%s: Cannot migrate from table %s because the WHERE caluse does not contain TTL column %s",
                          sql, targetTable.getTypeName(), ttl.getName()));
              }
          }
      }