async def METHOD_NAME(socks5_server):
    """
    Test if sending a UDP packet without a successful association fails.
    """
    await socks5_server.start()
    client = Socks5Client(('127.0.0.1', socks5_server.port), Mock())
    with pytest.raises(Socks5Error):
        client.sendto(b'\x00', ('127.0.0.1', 123))