### Question:
Assert { public static void isFalse(boolean bool, String messagePattern, Object... args) { if (bool) { throw new IllegalArgumentException(MessageFormat.format(messagePattern, args)); } }  static void isNull(Object obj); static void isNull(Object obj, String messagePattern, Object... args); static void notNull(Object obj); static void notNull(Object obj, String messagePattern, Object... args); static void isTrue(boolean bool, String messagePattern, Object... args); static void isFalse(boolean bool, String messagePattern, Object... args); static IllegalStateException shouldNeverHappen(Throwable th);  }### Answer:
@Test public void testIsFalse_Ok() throws Exception { isFalse(false, "msg"); }
@Test(expectedExceptions = IllegalArgumentException.class) public void testIsFalse_Fail() throws Exception { isFalse(true, "msg"); }