In my Java program, I get NullPointerException in my HashMap even after initialising and putting values to the HashMap.

```
    LinkedHashMap<Short,BigInteger> ft = new LinkedHashMap<Short,BigInteger>(5);

    ft.put( (short) 1, BigInteger.valueOf(A));
    ft.put( (short) 2, BigInteger.valueOf(B));
    System.out.println(ft.isEmpty());
    System.out.println(ft.get((short)1));
    System.out.println(ft.get((short)2));
    System.out.println(ft.containsKey(1));
    System.out.println(ft.containsValue(1));

```