old_contents: import pytest
  from api.base.settings.defaults import API_BASE
  
  @pytest.mark.django_db
  class TestAddonsList:
  
      def test_filter_by_category(self, app):
          url = '/{}addons/'.format(API_BASE)
          storage_url = '{}?filter[categories]=storage'.format(url)
          citations_url = '{}?filter[categories]=citations'.format(url)
  
          storage_data = app.get(storage_url).json['data']
          citations_data = app.get(citations_url).json['data']
  
          for addon in storage_data:
              assert 'storage' in addon['attributes']['categories']
  
          for addon in citations_data:
              assert 'citations' in addon['attributes']['categories']
  
new_contents: import pytest
  
  from api.base.settings.defaults import API_BASE
  
  @pytest.mark.django_db
  class TestAddonsList:
  
      def test_filter_by_category(self, app):
          url = '/{}addons/'.format(API_BASE)
          url_storage = '{}?filter[categories]=storage'.format(url)
          url_citations = '{}?filter[categories]=citations'.format(url)
  
          data_storage = app.get(url_storage).json['data']
          data_citations = app.get(url_citations).json['data']
  
          for addon in data_storage:
              assert 'storage' in addon['attributes']['categories']
  
          for addon in data_citations:
              assert 'citations' in addon['attributes']['categories']
  
subject: Fix namings