def monkeypatch_machine():

    from mock import Mock

    import uuid
    import machine

    # Some primitives.
    machine.enable_irq = Mock()
    machine.disable_irq = Mock()
    machine.unique_id = lambda: str(uuid.uuid4().fields[-1])[:5].encode()
    machine.freq = Mock(return_value=42000000)
    machine.idle = Mock()

    # Reset cause and wake reason.
    machine.PWRON_RESET = 0
    machine.HARD_RESET = 1
    machine.WDT_RESET = 2
    machine.DEEPSLEEP_RESET = 3
    machine.SOFT_RESET = 4
    machine.BROWN_OUT_RESET = 5

    machine.PWRON_WAKE = 0
    machine.GPIO_WAKE = 1
    machine.RTC_WAKE = 2
    machine.ULP_WAKE = 3

    machine.reset_cause = Mock(return_value=0)
    machine.wake_reason = wake_reason