old_contents: import django_filters
  
  from rest_framework import filters
  from rest_framework.serializers import ValidationError
  
  from core.models import AtmosphereUser, MaintenanceRecord
  from core.query import only_current
  
  from api.permissions import CanEditOrReadOnly
  from api.v2.serializers.details import MaintenanceRecordSerializer
  from api.v2.views.base import AuthOptionalViewSet
  
  
  class MaintenanceRecordFilterBackend(filters.BaseFilterBackend):
      """
      Filter MaintenanceRecords using the request_user and 'query_params'
      """
      def filter_queryset(self, request, queryset, view):
          request_params = request.query_params
          active = request_params.get('active')
          if isinstance(active, basestring) and active.lower() == 'true'\
                  or isinstance(active, bool) and active:
              queryset = MaintenanceRecord.active()
          return queryset
  
  class MaintenanceRecordViewSet(AuthOptionalViewSet):
  
      """
      API endpoint that allows records to be viewed or edited.
      """
      http_method_names = ['get', 'post', 'put', 'patch', 'head', 'options', 'trace']
      queryset = MaintenanceRecord.objects.order_by('-start_date')
      permission_classes = (CanEditOrReadOnly,)
      serializer_class = MaintenanceRecordSerializer
      filter_backends = (filters.DjangoFilterBackend, filters.SearchFilter, MaintenanceRecordFilterBackend)
  
new_contents: import django_filters
  
  from rest_framework import filters
  from rest_framework.serializers import ValidationError
  
  from core.models import AtmosphereUser, MaintenanceRecord
  from core.query import only_current
  
  from api.permissions import CanEditOrReadOnly
  from api.v2.serializers.details import MaintenanceRecordSerializer
  from api.v2.views.base import AuthOptionalViewSet
  
  
  class MaintenanceRecordFilterBackend(filters.BaseFilterBackend):
      """
      Filter MaintenanceRecords using the request_user and 'query_params'
      """
      def filter_queryset(self, request, queryset, view):
          request_params = request.query_params
          active = request_params.get('active')
          if isinstance(active, basestring) and active.lower() == 'true'\
                  or isinstance(active, bool) and active:
              queryset = MaintenanceRecord.active()
          return queryset
  
  class MaintenanceRecordViewSet(AuthOptionalViewSet):
  
      """
      API endpoint that allows records to be viewed or edited.
      """
      http_method_names = ['get', 'post', 'put', 'patch', 'delete', 'head', 'options', 'trace']
      queryset = MaintenanceRecord.objects.order_by('-start_date')
      permission_classes = (CanEditOrReadOnly,)
      serializer_class = MaintenanceRecordSerializer
      filter_backends = (filters.DjangoFilterBackend, filters.SearchFilter, MaintenanceRecordFilterBackend)
  
subject: Add 'DELETE' operation to Maintenance Record