#fixed code
                                @Test
    public void testRemove() throws SerializationException {
        FakeAuth nullValue = redisCache.remove(null);
        assertThat(nullValue, is(nullValue()));

        String testKey = "billy";
        byte[] testKeyBytes = keySerializer.serialize(testPrefix + testKey);
        FakeAuth testValue = new FakeAuth(3, "client");
        byte[] testValueBytes = valueSerializer.serialize(testValue);
        when(redisManager.get(testKeyBytes)).thenReturn(testValueBytes);
        FakeAuth actualValue = redisCache.remove(testKey);
        assertThat(actualValue.getId(), is(3));
        assertThat(actualValue.getRole(), is("client"));
    }
#vulnerable code 
                                @Test
    public void testRemove() {
        redisCache.remove(null);
        FakeSession actualValue = redisCache.remove(testKey);
        assertThat(actualValue.getId(), is(3));
        assertThat(actualValue.getName(), is("jack"));
    } 
                            #location 5 
                            #vulnerability type NULL_DEREFERENCE