def test_fingerprintsha256(self):
        """
        fingerprint method generates key fingerprint in
        L{FingerprintFormats.SHA256-BASE64} format if explicitly specified.
        """
        self.assertEqual(
            keys.Key(self.rsaObj).fingerprint(
                keys.FingerprintFormats.SHA256_BASE64),
            'FBTCOoknq0mHy+kpfnY9tDdcAJuWtCpuQMaV3EsvbUI=')
        self.assertEqual(
            keys.Key(self.dsaObj).fingerprint(
                keys.FingerprintFormats.SHA256_BASE64),
            'Wz5o2YbKyxOEcJn1au/UaALSVruUzfz0vaLI1xiIGyY=')

        fingerprint method generates key fingerprint in
        L{FingerprintFormats.SHA256-BASE64} format if explicitly specified.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/conch/test/test_keys.py