@Test
	    public void shouldGetExceptionWhenAgeLessThan0() {
	        // given
	        Person person = new Person();
	        // when
	        when(person).setAge(-1);
	        // then
	        assertThat(caughtException(), allOf(
	                instanceOf(IllegalArgumentException.class)
	                , hasMessage("age is invalid")
	                ,hasNoCause()));
	    }
	  第一種土鱉,第二種簡潔,第四種靠譜。