remove size when initializing map

Author: hongkuancn

cache.go

@@ -467,7 +467,7 @@ func (c *Cache[K, V]) Items() map[K]*Item[K, V] {
 	c.items.mu.RLock()
 	defer c.items.mu.RUnlock()
 
-	items := make(map[K]*Item[K, V], len(c.items.values))
+	items := make(map[K]*Item[K, V])
 	for k, elem := range c.items.values {
 		item := elem.Value.(*Item[K, V])
 		if item != nil && !item.isExpiredUnsafe() {