Util { public static String formatDuration(String durationStr) { return durationStr .substring(2) .replace("H", "h ") .replace("M", "m ") .replace('S', 's'); } private  Util(); static String formatDuration(String durationStr);  }
@Test public void test_format_duration() { String actual = Util.formatDuration("PT22H23M2S"); assertThat(actual).isEqualTo("22h 23m 2s"); }