### Question:
LoggingFunctions { public static String getSimpleDate(final long date) { return String.format("%1$tY/%1$tm/%1$td %1$tH:%1$tM:%1$tS.%1$tL", date); } private  LoggingFunctions(); static String getSimpleDate(final long date); static String getShortDate(final long date); static String getStackTraceString(final Throwable throwable); static void startLogging(final Logger logger, final Level level); static void startLogging(final Level level); static void startLogging(); static void startDebugLogging();  }### Answer:
@Test public void testGetSimpleDatePerformance() { LOG.log(Level.SEVERE, this.getClass().getName() + " 単純な日付の生成テスト"); final int loop = 100_000; long sum = 0; final long start = System.nanoTime(); for (int i = 0; i < loop; i++) { sum += LoggingFunctions.getSimpleDate(i).hashCode(); } final long end = System.nanoTime(); LOG.log(Level.SEVERE, this.getClass().getName() + " 繰り返し:" + loop + " 秒数:" + ((end - start) / 1_000_000_000.0) + " チェックサム:" + sum); }