def test_propertyGetter(self):
        """
        When L{deprecatedProperty} is used on a C{property}, accesses raise a
        L{DeprecationWarning} and getter docstring is updated to inform the
        version in which it was deprecated. C{deprecatedVersion} attribute is
        also set to inform the deprecation version.
        """
        obj = ClassWithDeprecatedProperty()

        obj.someProperty

        self.assertDocstring(
            ClassWithDeprecatedProperty.someProperty,
            [
                'Getter docstring.',
                '@return: The property.',
                'Deprecated in Twisted 1.2.3.',
                ],
            )
        ClassWithDeprecatedProperty.someProperty.deprecatedVersion = Version(
            'Twisted', 1, 2, 3)

        message = (
            'twisted.python.test.test_deprecate.ClassWithDeprecatedProperty.'
            'someProperty was deprecated in Twisted 1.2.3'
            )
        warnings = self.flushWarnings([self.test_propertyGetter])
        self.assertEqual(1, len(warnings))
        self.assertEqual(DeprecationWarning, warnings[0]['category'])
        self.assertEqual(message, warnings[0]['message'])

        When L{deprecatedProperty} is used on a C{property}, accesses raise a
        L{DeprecationWarning} and getter docstring is updated to inform the
        version in which it was deprecated. C{deprecatedVersion} attribute is
        also set to inform the deprecation version.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/python/test/test_deprecate.py