GroupBy week in querydsl

I get error

'week' is not a recognized built-in function name.

When trying to do this request:

var queryList = from(indexValue)
        .select(indexValue.value.avg().castToNum(BigDecimal.class))
        .groupBy(indexValue.day.week())
        .fetch();

But everything is ok, when i use indexValue.day.month() or indexValue.day.year(). How can i fix it?