    @Test
    public void testGetSmallestAndLargest() {

        Map<String, String> mapIO = new HashMap<String, String>() {{
            put("welcometojava", "ava\nwel");
        }};

        for (Map.Entry<String, String> io : mapIO.entrySet()) {
            String ret = SubStr.getSmallestAndLargest(io.getKey(), 3);
            Assert.assertEquals(io.getValue(), ret);
        }
    }