class SanitisedHttpHeaderFormatter {

    public String format(HttpHeaders headers) {
        return StreamSupport.stream(headers.spliterator(), false)
                .map(this::hideOrFormatHeader)
                .collect(joining(", "));
    }

    public  SanitisedHttpHeaderFormatter(List<String> headersToHide, List<String> cookiesToHide);

}