protected String resolveKey(String key) {
		Matcher matcher = PATTERN.matcher(key);
		StringBuffer sb = new StringBuffer();
		while (matcher.find()) {
			matcher.appendReplacement(sb, matcher.group(1).toUpperCase());
		}
		matcher.appendTail(sb);
		return sb.toString();
	}
refer
https://github.com/alibaba/spring-cloud-alibaba/issues/2872
https://github.com/alibaba/spring-cloud-alibaba/issues/2869 .
spring-cloud-alibaba-starters/spring-alibaba-nacos-config/src/main/java/com/alibaba/cloud/nacos/NacosConfigProperties.java