def test__guessStringType(self):
        """
        Test that the _guessStringType method guesses string types
        correctly.
        """
        self.assertEqual(
            keys.Key._guessStringType(keydata.publicRSA_openssh),
            'public_openssh')
        self.assertEqual(
            keys.Key._guessStringType(keydata.publicDSA_openssh),
            'public_openssh')
        self.assertEqual(
            keys.Key._guessStringType(keydata.publicECDSA_openssh),
            'public_openssh')
        self.assertEqual(
            keys.Key._guessStringType(keydata.privateRSA_openssh),
            'private_openssh')
        self.assertEqual(
            keys.Key._guessStringType(keydata.privateRSA_openssh_new),
            'private_openssh')
        self.assertEqual(
            keys.Key._guessStringType(keydata.privateDSA_openssh),
            'private_openssh')
        self.assertEqual(
            keys.Key._guessStringType(keydata.privateDSA_openssh_new),
            'private_openssh')
        self.assertEqual(
            keys.Key._guessStringType(keydata.privateECDSA_openssh),
            'private_openssh')
        self.assertEqual(
            keys.Key._guessStringType(keydata.privateECDSA_openssh_new),
            'private_openssh')
        self.assertEqual(
            keys.Key._guessStringType(keydata.publicRSA_lsh), 'public_lsh')
        self.assertEqual(
            keys.Key._guessStringType(keydata.publicDSA_lsh), 'public_lsh')
        self.assertEqual(
            keys.Key._guessStringType(keydata.privateRSA_lsh), 'private_lsh')
        self.assertEqual(
            keys.Key._guessStringType(keydata.privateDSA_lsh), 'private_lsh')
        self.assertEqual(
            keys.Key._guessStringType(keydata.privateRSA_agentv3), 'agentv3')
        self.assertEqual(
            keys.Key._guessStringType(keydata.privateDSA_agentv3), 'agentv3')
        self.assertEqual(
            keys.Key._guessStringType(
                b'\x00\x00\x00\x07ssh-rsa\x00\x00\x00\x01\x01'),
            'blob')
        self.assertEqual(
            keys.Key._guessStringType(
                b'\x00\x00\x00\x07ssh-dss\x00\x00\x00\x01\x01'),
            'blob')
        self.assertEqual(keys.Key._guessStringType(b'not a key'), None)

        Test that the _guessStringType method guesses string types
        correctly.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/conch/test/test_keys.py