public static boolean hasNonZeroContentLengthHeader(ZuulMessage msg) {
        Integer contentLengthVal = getContentLengthIfPresent(msg);
        return (contentLengthVal != null) && (contentLengthVal > 0);
    }
Ensure decoded new lines are not propagated in headers, in order to prevent XSS

@param input - decoded header string
@return - clean header string
zuul-core/src/main/java/com/netflix/zuul/util/HttpUtils.java