How to use the resilient.primitives.Cancellable function in resilient

def __init__(self, gf, *args, group=0, **kwargs):
        task = gf(TaskId(Cancellable.task_no), *args, **kwargs)
        if task in self.tasks:
            raise ValueError('Task already exists.')
        self.tasks[Cancellable.task_no] = [task, group, None]
        self.task_no = Cancellable.task_no  # For subclass
        Cancellable.task_no += 1
        self.task = task

def new_gen(*args, **kwargs):
        if isinstance(args[0], TaskId):  # Not a bound method
            task_id = args[0]
            g = f(*args[1:], **kwargs)
        else:  # Task ID is args[1] if a bound method
            task_id = args[1]
            args = (args[0],) + args[2:]
            g = f(*args, **kwargs)
        try:
            res = await g
            return res
        finally:
            NamedTask._stopped(task_id)
    return new_gen

class NamedTask(Cancellable):
    instances = {}

    @classmethod
    async def cancel(cls, name, nowait=True):
        if name in cls.instances:
            await cls.cancel_all(group=name, nowait=nowait)
            return True
        return False

    @classmethod
    def is_running(cls, name):
        return cls._is_running(group=name)

    @classmethod
    def _stopped(cls, task_id):  # On completion remove it
        name = cls._get_group(task_id())  # Convert task_id to task_no