#vulnerable code 
                                public void testAtomicReference() throws Exception
    {
        ObjectMapper mapper = new ObjectMapper();
        AtomicReference<long[]> value = mapper.readValue("[1,2]",
                new com.fasterxml.jackson.core.type.TypeReference<AtomicReference<long[]>>() { });
        Object ob = value.get();
        assertNotNull(ob);
        assertEquals(long[].class, ob.getClass());
        long[] longs = (long[]) ob;
        assertNotNull(longs);
        assertEquals(2, longs.length);
        assertEquals(1, longs[0]);
        assertEquals(2, longs[1]);
    } 
                            #location 6 
                            #vulnerability type NULL_DEREFERENCE
#fixed code
                                public void testAtomicReference() throws Exception
    {
        AtomicReference<long[]> value = MAPPER.readValue("[1,2]",
                new com.fasterxml.jackson.core.type.TypeReference<AtomicReference<long[]>>() { });
        Object ob = value.get();
        assertNotNull(ob);
        assertEquals(long[].class, ob.getClass());
        long[] longs = (long[]) ob;
        assertNotNull(longs);
        assertEquals(2, longs.length);
        assertEquals(1, longs[0]);
        assertEquals(2, longs[1]);
    }