def test_verifyDSA(self):
        """
        A known-good DSA signature verifies successfully.
        """
        key = keys.Key.fromString(keydata.publicDSA_openssh)
        self.assertTrue(key.verify(self.dsaSignature, b''))
        self.assertFalse(key.verify(self.dsaSignature, b'a'))
        self.assertFalse(key.verify(self.rsaSignature, b''))

        A known-good DSA signature verifies successfully.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/conch/test/test_keys.py