public static <T extends Collection<E>, E> T removeNull(T collection) {
		return filter(collection, Objects::nonNull);
	}
@Test
	public void removeNullTest() {
		final ArrayList<String> list = CollUtil.newArrayList("a", "b", "c", null, "", "  ");

		final ArrayList<String> filtered = CollUtil.removeNull(list);

		// 原地过滤
		assertSame(list, filtered);
		assertEquals(CollUtil.newArrayList("a", "b", "c", "", "  "), filtered);
	}