### Question:
StringFormatUtils { public static String addAtEndIfNotPresent(final String string, final String suffix) { return string == null ? suffix : !string.endsWith(suffix) ? string + suffix : string; } private  StringFormatUtils(); static String addAtEndIfNotPresent(final String string, final String suffix);  }### Answer:
@Test public void testAddAtEndIfNotPresent() { assertEquals(expected, StringFormatUtils.addAtEndIfNotPresent(string, suffix)); }