assertThat(map.containsValue("test2"), is(true));
        assertThat(map.containsValue("test3"), is(not(true)));
    }

    /**
     * @throws Exception
     */
    @Test
    public void testContainsKey() throws Exception {
        assertThat(map.containsKey("2"), is(true));
        assertThat(map.containsKey("3"), is(not(true)));
        map.put("3", null);
        assertThat(map.containsKey("3"), is(true));
    }