[Django]-Django prefetch_related with limit

I think there is a workaround now to in django new version as we have OuterRef and Subquery.

from django.db.models import OuterRef, Subquery, Prefetch

subqry = Subquery(Comment.objects \
    .filter(user_id=OuterRef('user_id')) \
    .values_list('id', flat=True)[:5])

User.objects.prefetch_related(
    Prefetch('comments', queryset=Comment.objects.filter(id__in=subqry)))

The only way to limit the number of prefetched related objects seems to be using Prefetch() and filtering on fileds. Using sliceing

User.objects.all().prefetch_related(
    Prefetch('msg_sent', queryset=UserMsg.objects.order_by('-created')[:10]))

returns an error

AssertionError: Cannot filter a query once a slice has been taken.

The only way to limit the number of related objects seems to be using filter on a value, for example

from datetime import datetime, timedelta
timelimit = datetime.now() - timedelta(days=365)

User.objects.all().prefetch_related(
    Prefetch('msg_sent', queryset=UserMsg.objects.filter(created__gte=timelimit)))

While that doesn’t return a fixed number, in may be useful in some situation, and it will reduce the number of prefetched objects.

thats what actually works for me django(2.1) (based on haseebahmad answer).
in order for prefetch_related to accept customize queryset: Prefetch
so:

from django.db.models import OuterRef, Subquery ,Prefetch

User.objects.all().prefetch_related(Prefetch('comment_set',  
queryset=Comment.objects.filter(id__in= 
Subquery(Comment.objects.filter(user_id=OuterRef('user_id')).
values_list('id', flat=True)[:1]))))

It is also possible to do by using CTE and ROW_NUMBER().

from django.db.models import Prefetch
from django.db.models.functions.window import RowNumber
from django_cte import With

cte = With(
    Comment.objects.annotate(
        row_number=Window(
            expression=RowNumber(),
            partition_by=F("user_id")
        )
    )
)
qs = cte.with_cte(cte).filter(row_number<=10)
users = User.objects.prefetch_related(
    Prefetch("comments", queryset=qs, to_attr="limited_comments")
)