public static String escape(char c) {
		final StringBuilder builder = new StringBuilder();
		if (RE_KEYS.contains(c)) {
			builder.append('\\');
		}
		builder.append(c);
		return builder.toString();
	}
@Test
	public void escapeTest() {
		//转义给定字符串，为正则相关的特殊符号转义
		final String escape = ReUtil.escape("我有个$符号{}");
		assertEquals("我有个\\$符号\\{\\}", escape);
	}