I'd like to write custom CacheLoader retrieving data via HTTP. I've started with dummy implementation ettending AbstractCacheLoader but I'm still not sure what should return from

Map<Object, Object> get(Fqn fqn) {...}

I wanted it to return constant value set by cacheloader config but when I read the result in my junit test, it's always null. Please can you explain or, even better, give me some simple example ?