public void moveToTail(){
  if (isTail() || isUnlinked()) {
    return;
  }
  lock.lock();
  try {
    if (isTail() || isUnlinked()) {
      return;
    }
    prev.next=next;
    next.prev=prev;
    next=sentinel;
    prev=sentinel.prev;
    sentinel.prev=this;
    prev.next=this;
  }
  finally {
    lock.unlock();
  }
}

public void moveToTail ( ) { if ( isTail ( ) || isUnlinked ( ) ) { return ; } lock . lock ( ) ; try { if ( isTail ( ) || isUnlinked ( ) ) { return ; } prev . next = next ; next . prev = prev ; next = sentinel ; prev = sentinel . prev ; sentinel . prev = this ; prev . next = this ; } finally { lock . unlock ( ) ; } }
moves the node to the tail . < p > if the node has been unlinked or is already at the tail , no - ops .
