def test_unsetComponent(self):
        """
        C{Componentized.setComponent} removes the cached component for the
        given interface.
        """
        componentized = components.Componentized()
        obj = object()
        componentized.setComponent(ITest, obj)
        componentized.unsetComponent(ITest)
        self.assertIsNone(componentized.getComponent(ITest))

        C{Componentized.setComponent} removes the cached component for the
        given interface.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/python/test/test_components.py