public static <T> String join(T[] array, CharSequence conjunction) {
		return join(array, conjunction, null, null);
	}
@Test
	public void joinTest() {
		String[] array = {"aa", "bb", "cc", "dd"};
		String join = ArrayUtil.join(array, ",", "[", "]");
		assertEquals("[aa],[bb],[cc],[dd]", join);

		Object array2 = new String[]{"aa", "bb", "cc", "dd"};
		String join2 = ArrayUtil.join(array2, ",");
		assertEquals("aa,bb,cc,dd", join2);
	}