public void insert(LinkedListNode prevNode) {
    mNextNode.mPrevNode = mPrevNode;
    mPrevNode.mNextNode = mNextNode;

    mPrevNode = prevNode;
    mNextNode = prevNode.mNextNode;
    prevNode.mNextNode.mPrevNode = this;
    prevNode.mNextNode = this;
  }
 public void remove() {
   mNextNode.mPrevNode = mPrevNode;
   mPrevNode.mNextNode = mNextNode;
 }