code: static <K, V> void reorder(LinkedDeque<Node<K, V>> deque, Node<K, V> node) {
      // An entry may be scheduled for reordering despite having been removed. This can occur when the
      // entry was concurrently read while a writer was removing it. If the entry is no longer linked
      // then it does not need to be processed.
      if (deque.contains(node)) {
        deque.moveToBack(node);
      }
    }
docs: Updates the node's location in the policy's deque.