old_contents: from django.http import HttpResponse
  
  
  def list_question_sets(request):
      return HttpResponse('Lol, udachi')
  
new_contents: import json
  from django.http import HttpResponse
  from maps.models import QuestionSet
  
  
  def list_question_sets(request):
      objects = QuestionSet.objects.all()
      items = []
      for obj in objects:
          items.append({
              'title': obj.title,
              'max_duration': obj.max_duration.seconds,
              'creator': {
                  'full_name': obj.creator.get_full_name()
              }
          })
      return HttpResponse(json.dumps(items))
  
subject: Add API method for question sets list