NewRegisteredRateLimiter returns a new RegisteredRateLimiater.

NewUIDCache returns a UIDCache.

Register all metrics.

GarbageCollector runs reflectors to watch for changes of managed API objects, funnels the results to a single-threaded dependencyGraphBuilder, which builds a graph caching the dependencies among objects.

GraphBuilder: based on the events supplied by the informers, GraphBuilder updates uidToNode, a graph that caches the dependencies as we know, and enqueues items to the attemptToDelete and attemptToOrphan.

RegisteredRateLimiter records the registered RateLimters to avoid duplication.

UIDCache is an LRU cache for uid.