### Question:
Utils { public static String sizeToStr(long size) { if (size < 2 * (1L << 10)) { return size + "b"; } if (size < 2 * (1L << 20)) { return String.format("%dKb", size / (1L << 10)); } if (size < 2 * (1L << 30)) { return String.format("%dMb", size / (1L << 20)); } return String.format("%dGb", size / (1L << 30)); }  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 sizeToStr() { Assert.assertEquals("1b", Utils.sizeToStr(1)); }