How to use the blinker.receiver_connected._clear_state function in blinker

def meta_received(sender, **kw):
        raise TypeError('boom')

    assert not blinker.receiver_connected.receivers
    blinker.receiver_connected.connect(meta_received)

    def receiver(sender, **kw):
        pass
    sig = blinker.Signal()

    assert_raises(TypeError, sig.connect, receiver)
    assert not sig.receivers
    assert not sig._by_receiver
    assert sig._by_sender == {blinker.base.ANY_ID: set()}

    blinker.receiver_connected._clear_state()

assert not blinker.receiver_connected.receivers
    blinker.receiver_connected.connect(meta_received)
    assert not sentinel

    def receiver(sender, **kw):
        pass
    sig = blinker.Signal()
    sig.connect(receiver)

    assert sentinel == [dict(sender=sig,
                             receiver_arg=receiver,
                             sender_arg=blinker.ANY,
                             weak_arg=True)]

    blinker.receiver_connected._clear_state()