text: from covid import types as tt
  
  import pytest
  
  
  class TestDescriptors:
      @pytest.fixture(scope="class")
      def cls(self):
          class Cls:
              cached = tt.cached(lambda x: 42)
  
          return Cls
  
      def test_cached_descriptors(self, cls):
          obj = cls()
          assert obj.cached == 42
          obj.cached = 0
          assert obj.cached == 0
  