### Question:
Utils { public static String repeat(String s, int n) { if (s.length() == 1) { byte[] bb = new byte[n]; Arrays.fill(bb, s.getBytes()[0]); String result = new String(bb); bb = null; return result; } else { StringBuilder ret = new StringBuilder(); for (int i = 0; i < n; i++) { ret.append(s); } return ret.toString(); } }  static String longToTimePeriod(long msec); static SecureRandom getRandom(); static String getNodeIdShort(String nodeId); static long toUnixTime(long javaTime); static long fromUnixTime(long unixTime); @SafeVarargs static T[] mergeArrays(T[]... arr); static String align(String s, char fillChar, int targetLen, boolean alignRight); static String repeat(String s, int n); static void showErrorAndExit(String message, String... messages); static void showWarn(String message, String... messages); static String sizeToStr(long size); static void sleep(long ms); @Deprecated static long time();  }### Answer:
@Test public void repeat() { Assert.assertEquals("aa", Utils.repeat("a", 2)); }