def test_blobEC(self):
        """
        Return the over-the-wire SSH format of the EC public key.
        """
        from cryptography import utils

        byteLength = (self.ecObj.curve.key_size + 7) // 8
        self.assertEqual(
            keys.Key(self.ecObj).blob(),
            common.NS(keydata.ECDatanistp256['curve']) +
            common.NS(keydata.ECDatanistp256['curve'][-8:]) +
            common.NS(b'\x04' +
               utils.int_to_bytes(
                 self.ecObj.private_numbers().public_numbers.x, byteLength) +
                   utils.int_to_bytes(
                   self.ecObj.private_numbers().public_numbers.y, byteLength))
            )

        Return the over-the-wire SSH format of the EC public key.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/conch/test/test_keys.py