How to get the value with key in pyramid_beaker for memcached?

Question

@cache_region('day', 'my_search_func')$
def _query(tags, num, searchid=None):
    ...

I used decorate API in beaker, then, can get the beaker.cache.Cache object through the code:

CacheManager(cache_regions=cache.cache_regions).get_cache_region('my_search_func', 'day')

My question is how to use the get_value of Cache class to retrive the specific key/value, I really don't how to make sure the key parameter for get_value function?

Thanks Kenny