async def test_connect_no_auth_supplied_when_required(self, r):
        """
        AuthenticationError should be raised when the server requires a
        password but one isn't supplied.
        """
        with pytest.raises(aioredis.AuthenticationError):
            await r.execute_command(
                "DEBUG", "ERROR", "ERR Client sent AUTH, but no password is set"
            )

        AuthenticationError should be raised when the server requires a
        password but one isn't supplied.
        
tests/test_connection_pool.py