func TestLRU_Add_ExistingKey_UpdatesValueAndExpiresAt(t *testing.T) {
	lru := lru.NewLRU[string, int](10, nil, time.Hour)
	lru.Add("key1", 1)
	lru.Add("key1", 2)

	if value, ok := lru.Get("key1"); !ok || value != 2 {
		t.Errorf("Expected value to be updated to 2, got %v", value)
	}
}

func TestLRU_Add_NewKey_AddsEntry(t *testing.T) {
	lru := lru.NewLRU[string, int](10, nil, time.Hour)
	lru.Add("key1", 1)

const numBuckets = 100

// NewLRU returns a new thread-safe cache with expirable entries.
//
// Size parameter set to 0 makes cache of unlimited size, e.g. turns LRU mechanism off.
//
// Providing 0 TTL turns expiring off.
//
// Delete expired entries every 1/100th of ttl value. Goroutine which deletes expired entries runs indefinitely.