def test_makedirsThrowsWithExistentDirectory(self):
        """
        C{FilePath.makedirs} throws an C{OSError} exception
        when called on a directory that already exists.
        """
        fp = filepath.FilePath(os.path.join(self.mktemp()))
        fp.makedirs()

        exception = self.assertRaises(OSError, fp.makedirs)

        self.assertEqual(exception.errno, errno.EEXIST)

        C{FilePath.makedirs} throws an C{OSError} exception
        when called on a directory that already exists.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/test/test_paths.py