def test_prereleaseAttributeDeprecated(self):
        """
        Accessing 'prerelease' on a Version is deprecated.
        """
        va = Version("whatever", 1, 0, 0, release_candidate=1)
        va.prerelease
        warnings = self.flushWarnings(
            [self.test_prereleaseAttributeDeprecated])
        self.assertEqual(len(warnings), 1)
        self.assertEqual(
            warnings[0]['message'],
            ("Accessing incremental.Version.prerelease was deprecated in "
             "Incremental 16.9.0. Use Version.release_candidate instead."))

        Accessing 'prerelease' on a Version is deprecated.
        
stackoverflow/venv/lib/python3.6/site-packages/incremental/tests/test_version.py