public static <T> String join(Iterator<T> iterator, CharSequence conjunction) {
		return StrJoiner.of(conjunction).append(iterator).toString();
	}
@Test
	public void joinWithFuncTest() {
		final ArrayList<String> list = CollUtil.newArrayList("1", "2", "3", "4");
		final String join = IterUtil.join(list.iterator(), ":", String::valueOf);
		assertEquals("1:2:3:4", join);
	}