How to use the flower.core.timer.Timer function in flower

def test_multiple_timer():
    r1 = []
    def f(now, t):
        r1.append(from_nanotime(now))

    r2 = []
    def f1(now, t):
        r2.append(from_nanotime(now))

    now = time.time()

    t = Timer(f, 0.4)
    t.start()

    t1 = Timer(f1, 0.1)
    t1.start()

    run()
    assert r1[0] > r2[0]
    assert (now + 0.39) <= r1[0] <= (now + 0.41), r1[0]
    assert (now + 0.09) <= r2[0] <= (now + 0.11), r2[0]

def test_repeat():
    r = []
    def f(now, t):
        if len(r) == 3:
            t.stop()
            return
        r.append(now)

    t = Timer(f, 0.01, 0.01)
    t.start()
    run()
    assert len(r) == 3
    assert r[2] > r[1]
    assert r[1] > r[0]

def test_multiple_timer():
    r1 = []
    def f(now, t):
        r1.append(from_nanotime(now))

    r2 = []
    def f1(now, t):
        r2.append(from_nanotime(now))

    now = time.time()

    t = Timer(f, 0.4)
    t.start()

    t1 = Timer(f1, 0.1)
    t1.start()

    run()
    assert r1[0] > r2[0]
    assert (now + 0.39) <= r1[0] <= (now + 0.41), r1[0]
    assert (now + 0.09) <= r2[0] <= (now + 0.11), r2[0]

def test_simple_timer():
    r_list = []
    def _func(now, t):
        r_list.append(from_nanotime(now))

    now = time.time()
    t = Timer(_func, 0.1)
    t.start()
    run()
    delay = r_list[0]
    assert (now + 0.09) <= delay <= (now + 0.11), delay

def idle():
    """ By using this function the current tasklet will be scheduled asap"""

    sched = core.get_scheduler()
    curr = core.getcurrent()
    def ready(now, h):
        curr.blocked = False
        sched.append(curr)
        core.schedule()

    t = timer.Timer(ready, 0.0001)
    t.start()

    curr.blocked = True
    core.schedule_remove()

def after_func(d, f, *args, **kwargs):
    """ AfterFunc waits for the duration to elapse and then calls f in
    its own coroutine. It returns a Timer that can be used to cancel the
    call using its stop method. """

    def _func(now, handle):
        core.tasklet(f)(*args, **kwargs)
        core.schedule()

    t = timer.Timer(_func, d)
    t.start()
    return t

def __init__(self, interval, label=''):
        super(Ticker, self).__init__(label=label)
        self._interval = interval
        self._timer = timer.Timer(self._tick, interval, interval)
        self._timer.start()

def sleep(seconds=0):
    if not seconds:
        return

    sched = get_scheduler()
    curr = getcurrent()

    c = channel()
    def ready(now, t):
        c.send(None)

    t = Timer(ready, seconds)
    t.start()
    c.receive()