CacheStore: { 
    del(key) => void; 
    flushAll() => void; 
    get<T>(key) => undefined | T; 
    set<T>(key, value) => void; 
}
Type declaration
del:function
- del(key): void
 Returns void
flushAll:function
- flushAll(): void
 Returns void
get:function
- get<T>(key): undefined | T
 Returns undefined | T
set:function
- set<T>(key, value): void
 Returns void
delete a key from the cache