code: void unlink(Node<K, V> node) {
      Node<K, V> next = node.getNextInVariableOrder();
      if (next != null) {
        Node<K, V> prev = node.getPreviousInVariableOrder();
        next.setPreviousInVariableOrder(prev);
        prev.setNextInVariableOrder(next);
      }
    }
docs: Removes the entry from its bucket, if scheduled.