### Question:
CommonUtils { public static <T extends Number> T parseNum(T num, T defaultInt) { return num == null ? defaultInt : num; }  static V putToConcurrentMap(ConcurrentMap<K, V> map, K key, V value); static boolean isTrue(String b); static boolean isTrue(Boolean b); static boolean isFalse(Boolean b); static boolean isFalse(String b); static boolean isEmpty(Collection collection); static boolean isNotEmpty(Collection collection); static boolean isEmpty(Map map); static boolean isNotEmpty(Map map); static boolean isEmpty(Object[] array); static boolean isNotEmpty(Object[] array); static T parseNum(T num, T defaultInt); static int parseInt(String num, int defaultInt); static long parseLong(String num, long defaultLong); static boolean parseBoolean(String bool, boolean defaultInt); static int[] parseInts(String nums, String sperator); static boolean listEquals(List<T> left, List<T> right); static String join(Collection collection, String separator);  }### Answer:
@Test public void testParseNum() { Assert.assertTrue(CommonUtils.parseNum(null, 123) == 123); Assert.assertTrue(CommonUtils.parseNum(1234, 123) == 1234); }