new_contents: 
  import pytest
  from diss import add_file
  from diss.settings import inventory, storage
  
  
  @pytest.fixture
  def record(request):
      record = add_file('hello.txt', key=b'0'*32)
  
      def fin():
          inventory.delete(record['id'])
          storage.delete(record['blob'])
      request.addfinalizer(fin)
      return record
  
subject: Fix add missing tests/fixtures.py