// or deleting it for being stale.
func (c *LRU[K, V]) Contains(key K) (ok bool) {
	c.mu.RLock()
	defer c.mu.RUnlock()
	_, ok = c.items[key]
	return ok
}

// Peek returns the key value (or undefined if not found) without updating
// the "recently used"-ness of the key.
func (c *LRU[K, V]) Peek(key K) (value V, ok bool) {
	c.mu.RLock()
	defer c.mu.RUnlock()
	var ent *Entry[K, V]
	if ent, ok = c.items[key]; ok {