### Question:
Check { public static <T> T notNull(T obj, String name) { if (obj == null) { throw new IllegalArgumentException(name + " cannot be null"); } return obj; }  static T notNull(T obj, String name); static List<T> notNullElements(List<T> list, String name); static String notEmpty(String str, String name); static List<String> notEmptyElements(List<String> list, String name); static String validIdentifier(String value, int maxLen, String name); static int gt0(int value, String name); static long gt0(long value, String name); static int ge0(int value, String name); static long ge0(long value, String name);  }### Answer:
@Test public void notNullNotNull() { assertEquals(Check.notNull("value", "name"), "value"); }
@Test(expected = IllegalArgumentException.class) public void notNullNull() { Check.notNull(null, "name"); }