Adding a new utility function that helps wrapping expensive functions like long-running API calls insie a cache function. Few gimmicks:

1. Have some TTL that invalidates the cache
2. Hash the function to easily use the cache without specifying a key
3. Add some validate function to allow invalidating the cache. This is handy when you want to search a list first with cached results but then do some network call in case something wasn't found in the cached results.