def verifyBuilt(self):
        """
        Verify that a sphinx project has been built.
        """
        htmlDir = self.sphinxDir.sibling('doc')
        self.assertTrue(htmlDir.isdir())
        doctreeDir = htmlDir.child("doctrees")
        self.assertFalse(doctreeDir.exists())

        self.verifyFileExists(htmlDir, 'index.html')
        self.verifyFileExists(htmlDir, 'genindex.html')
        self.verifyFileExists(htmlDir, 'objects.inv')
        self.verifyFileExists(htmlDir, 'search.html')
        self.verifyFileExists(htmlDir, 'searchindex.js')

        Verify that a sphinx project has been built.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/python/test/test_release.py