public static String get(String regex, CharSequence content, int groupIndex) {
		if (null == content || null == regex) {
			return null;
		}

		final Pattern pattern = PatternPool.get(regex, Pattern.DOTALL);
		return get(pattern, content, groupIndex);
	}
@Test
	void getEmailAddressTest() {
		String mail = "姓名<a.b@Hutool.cn>";
		String s = ReUtil.get(PatternPool.EMAIL, mail, 0);
		assertEquals("a.b@Hutool.cn", s);

		mail = "姓名 <a.b@Hutool.cn>";
		s = ReUtil.get(PatternPool.EMAIL, mail, 0);
		assertEquals("a.b@Hutool.cn", s);

		mail = "a.b@Hutool.cn";
		s = ReUtil.get(PatternPool.EMAIL, mail, 0);
		assertEquals("a.b@Hutool.cn", s);
	}