@Override
    @SuppressWarnings({ "unchecked", "rawtypes" })
    public Q from(SubQueryExpression<?> subQuery, Path<?> alias) {
        return queryMixin.from((Expression) ExpressionUtils.as((Expression) subQuery, alias));
    }
Add the given Expression as a query flag

@param position position
@param flag query flag
@return the current object
querydsl-sql/src/main/java/com/querydsl/sql/ProjectableSQLQuery.java