How to use the cachetools.cache.Cache function in cachetools

import collections

from .cache import Cache


class LRUCache(Cache):
    """Least Recently Used (LRU) cache implementation."""

    def __init__(self, maxsize, getsizeof=None):
        Cache.__init__(self, maxsize, getsizeof)
        self.__order = collections.OrderedDict()

    def __getitem__(self, key, cache_getitem=Cache.__getitem__):
        value = cache_getitem(self, key)
        self.__update(key)
        return value

    def __setitem__(self, key, value, cache_setitem=Cache.__setitem__):
        cache_setitem(self, key, value)
        self.__update(key)

    def __delitem__(self, key, cache_delitem=Cache.__delitem__):

def pop(self, *args, **kwargs):
        with self.__timer:
            return Cache.pop(self, *args, **kwargs)

def __init__(self, maxsize, getsizeof=None):
        if getsizeof:
            self.getsizeof = getsizeof
        if self.getsizeof is not Cache.getsizeof:
            self.__size = dict()
        self.__data = dict()
        self.__currsize = 0
        self.__maxsize = maxsize

else:
            time = self.__time
        self.__nesting += 1
        return time

    def __exit__(self, *exc):
        self.__nesting -= 1

    def __reduce__(self):
        return _Timer, (self.__timer,)

    def __getattr__(self, name):
        return getattr(self.__timer, name)


class TTLCache(Cache):
    """LRU Cache implementation with per-item time-to-live (TTL) value."""

    def __init__(self, maxsize, ttl, timer=time.monotonic, getsizeof=None):
        Cache.__init__(self, maxsize, getsizeof)
        self.__root = root = _Link()
        root.prev = root.next = root
        self.__links = collections.OrderedDict()
        self.__timer = _Timer(timer)
        self.__ttl = ttl

    def __contains__(self, key):
        try:
            link = self.__links[key]  # no reordering
        except KeyError:
            return False
        else:

import random

from .cache import Cache


# random.choice cannot be pickled in Python 2.7
def _choice(seq):
    return random.choice(seq)


class RRCache(Cache):
    """Random Replacement (RR) cache implementation."""

    def __init__(self, maxsize, choice=random.choice, getsizeof=None):
        Cache.__init__(self, maxsize, getsizeof)
        # TODO: use None as default, assing to self.choice directly?
        if choice is random.choice:
            self.__choice = _choice
        else:
            self.__choice = choice

    @property
    def choice(self):
        """The `choice` function used by the cache."""
        return self.__choice

    def popitem(self):

def expire(self, time=None):
        """Remove expired items from the cache."""
        if time is None:
            time = self.__timer()
        root = self.__root
        curr = root.next
        links = self.__links
        cache_delitem = Cache.__delitem__
        while curr is not root and curr.expire < time:
            cache_delitem(self, curr.key)
            del links[curr.key]
            next = curr.next
            curr.unlink()
            curr = next

    def __setitem__(self, key, value, cache_setitem=Cache.__setitem__):
        with self.__timer as time:
            self.expire(time)
            cache_setitem(self, key, value)
        try:
            link = self.__getlink(key)
        except KeyError:
            self.__links[key] = link = _Link(key)
        else:
            link.unlink()
        link.expire = time + self.__ttl
        link.next = root = self.__root
        link.prev = prev = root.prev
        prev.next = root.prev = link