def corofunc1():
            called[0] += 1
            return event.ReturnValue(insert_events=[evt2], append_events=[evt])
def wait_time_gen():
        count = 0
        while True:
            rand = random.randrange(round(interval.total_seconds()))
            tmp = round(start + interval.total_seconds() * count + rand - loop.time())
            yield tmp
            count += 1