text: import random
  
  from django.db.models import F
  from django.shortcuts import get_object_or_404
  from django_filters.rest_framework import DjangoFilterBackend
  from rest_framework import filters, generics, status
  from rest_framework.permissions import IsAuthenticated
  from rest_framework.response import Response
  
  from projects.models import Project
  from examples.filters import ExampleFilter
  from examples.models import Example
  from examples.serializers import ExampleSerializer
  from projects.permissions import IsProjectAdmin, IsProjectStaffAndReadOnly
  
  
  class ExampleList(generics.ListCreateAPIView):
      serializer_class = ExampleSerializer
      permission_classes = [IsAuthenticated & (IsProjectAdmin | IsProjectStaffAndReadOnly)]
      filter_backends = (DjangoFilterBackend, filters.SearchFilter, filters.OrderingFilter)
      ordering_fields = ('created_at', 'updated_at')
      search_fields = ('text', 'filename')
      model = Example
      filter_class = ExampleFilter
  
      @property
      def project(self):
          return get_object_or_404(Project, pk=self.kwargs['project_id'])
  
      def get_queryset(self):
          queryset = self.model.objects.filter(project=self.project)
          if self.project.random_order:
              # Todo: fix the algorithm.
              random.seed(self.request.user.id)
              value = random.randrange(2, 20)
              queryset = queryset.annotate(sort_id=F('id') % value).order_by('sort_id', 'id')
          else:
              queryset = queryset.order_by('created_at')
          return queryset
  
      def perform_create(self, serializer):
          serializer.save(project=self.project)
  
      def delete(self, request, *args, **kwargs):
          queryset = self.project.examples
          delete_ids = request.data['ids']
          if delete_ids:
              queryset.filter(pk__in=delete_ids).delete()
          else:
              queryset.all().delete()
          return Response(status=status.HTTP_204_NO_CONTENT)
  
  
  class ExampleDetail(generics.RetrieveUpdateDestroyAPIView):
      queryset = Example.objects.all()
      serializer_class = ExampleSerializer
      lookup_url_kwarg = 'example_id'
      permission_classes = [IsAuthenticated & (IsProjectAdmin | IsProjectStaffAndReadOnly)]
  