public void removeAll (int toRemove ，LinkedNode head) {
    if (head == null) {
        return null;
    }
    LinkedNode pre = head;
    LinkedNode node = head.next;
    while (node != null) {
        if (node.data == toRemove) {
            pre.next = node.next;
            node = pre.next;
        } else {
            pre = pre.next;
            node = node.next;
        }
    }
    if (head.data == toRemove) {
        head = head.next;
    }
    return head;
}