insert element at middle in Doubly Link List Implementation

 /* Function to insert element at position */
    public void insertAtPos(int val , int pos)
    {
        Node nptr = new Node(val, null, null);    
        if (pos == 1)
        {
            insertAtStart(val);
            return;
        }            
        Node ptr = start;
        for (int i = 2; i <= size; i++)
        {
            if (i == pos)
            {
                Node tmp = ptr.getLinkNext();
                ptr.setLinkNext(nptr);
                nptr.setLinkPrev(ptr);
                nptr.setLinkNext(tmp);
                tmp.setLinkPrev(nptr);
            }
            ptr = ptr.getLinkNext();            
        }
        size++ ;
    }

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