def test_getPrivateKeys(self):
        """
        Will return the available private keys in the data directory, ignoring
        key files which failed to be loaded.
        """
        keys = self.factory.getPrivateKeys()
        self.assertEqual(len(keys), 2)
        keyTypes = keys.keys()
        self.assertEqual(set(keyTypes), set([b'ssh-rsa', b'ssh-dss']))
        self.assertEqual(self.mockos.seteuidCalls, [])
        self.assertEqual(self.mockos.setegidCalls, [])

        Will return the available private keys in the data directory, ignoring
        key files which failed to be loaded.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/conch/test/test_openssh_compat.py