How to use the flower.core.sched.getcurrent function in flower

def switch(self):
        if not self.running:
            self._runtask = tasklet(self.run)()

        getcurrent().remove()
        self._runtask.switch()

def _channel_action(self, arg, d):
        """
        d == -1 : receive
        d ==  1 : send

        the original CStackless has an argument 'stackl' which is not used
        here.

        'target' is the peer tasklet to the current one
        """

        assert abs(d) == 1

        do_schedule = False
        curr = getcurrent()
        source = ChannelWaiter(curr, get_scheduler(), arg)

        if d > 0:
            if not self.capacity:
                cando = self.balance < 0
            else:
                cando = len(self.recvq) <= self.capacity
            dir = d
        else:
            if not self.capacity:
                cando = self.balance > 0
            else:
                cando = len(self.sendq) <= self.capacity
            dir = 0

        if _channel_callback is not None:

if d > 0:
            if not self.capacity:
                cando = self.balance < 0
            else:
                cando = len(self.recvq) <= self.capacity
            dir = d
        else:
            if not self.capacity:
                cando = self.balance > 0
            else:
                cando = len(self.sendq) <= self.capacity
            dir = 0

        if _channel_callback is not None:
            with self._lock:
                _channel_callback(self, getcurrent(), dir, not cando)

        if cando:
            # there is somebody waiting
            try:
                target = self.dequeue(d)
            except IndexError:
                # capacity is not None but nobody is waiting
                if d > 0:
                    self.enqueue(dir, ChannelWaiter(None, None, arg))
                return None

            source.arg, target.arg = target.arg, source.arg
            if target.task is not None:
                if self.schedule_all:
                    target.scheduler.unblock(target.task)
                    do_schedule = True

def idle(self, handle):
        if getcurrent() is self._runtask:
            schedule()