void (Entry<K, V> e) { Entry<K, V> top = this.top; if (top == e) { return; } Entry<K, V> prev = e.previous; Entry<K, V> next = e.next; prev.next = next; if (next != null) { next.previous = prev; } else { back = prev; } top.previous = e; e.next = top; e.previous = null; this.top = e; }