def METHOD_NAME(self):
    test_cases = [
        ('invalid/le-staging-chain.pem', 'Fake LE Root X1'),
        ('invalid/glbc_le_stage_cert.pem', 'Fake LE Intermediate X1'),
        ('invalid/expired_cert.pem', 'Zintermediate'),
        ('valid/cert.pem', 'Whistleblowing Solutions I.S. S.r.l.'),
    ]
    for cert_path, issuer_name in test_cases:
        p = os.path.join(self.test_data_dir, cert_path)
        with open(p, 'r') as f:
            x509 = crypto.load_certificate(FILETYPE_PEM, f.read())
        res = tls.parse_issuer_name(x509)
        self.assertEqual(res, issuer_name)