@Override
        public Enumeration getHeaderNames() {
            Enumeration e = super.getHeaderNames();
            List<String> list = new ArrayList<>();
            while (e.hasMoreElements()) {
                String name = (String) e.nextElement();
                if ("Content-Length".equalsIgnoreCase(name)) {
                    continue;
                } else if ("Content-MD5".equalsIgnoreCase(name)) {
                    continue;
                } else if ("Content-Encoding".equalsIgnoreCase(name)) {
                    continue;
                } else if ("Content-Type".equalsIgnoreCase(name)) {
                    list.add(getContentType());
                } else {
                    list.add(name);
                }
            }
            return Collections.enumeration(list);
        }
@see jakarta.servlet.http.HttpServletRequestWrapper#getHeaderNames()
src/nu/validator/servlet/MultipartFormDataFilter.java