public static String capitaliseFirstLetter(String string) {
        if (string == null || string.length() == 0) {
            return string;
        } else {
            return string.substring(0, 1).toUpperCase() + string.substring(1);
        }
    }
@Test
    public void testCapitaliseFirstLetter() {
        assertEquals(capitaliseFirstLetter(""), (""));
        assertEquals(capitaliseFirstLetter("a"), ("A"));
        assertEquals(capitaliseFirstLetter("aa"), ("Aa"));
        assertEquals(capitaliseFirstLetter("A"), ("A"));
        assertEquals(capitaliseFirstLetter("Ab"), ("Ab"));
    }