@Override
    public Q withRecursive(Path<?> alias, SubQueryExpression<?> query) {
        queryMixin.addFlag(new QueryFlag(QueryFlag.Position.WITH, SQLTemplates.RECURSIVE));
        return with(alias, query);
    }
Creates an union expression for the given subqueries

@param <RT>
@param alias alias for union
@param sq subqueries
@return the current object
querydsl-sql/src/main/java/com/querydsl/sql/ProjectableSQLQuery.java