class HttpHeadersImpl implements HttpHeaders {

    @Override
    public String getHeaderString(String name) {
        List<String> headerValues = nettyHttpHeaders.getAll(name);
        if (headerValues == null) {
            return null;
        }
        StringBuilder sb = new StringBuilder();
        for (int i = 0; i < headerValues.size(); i++) {
            String value = headerValues.get(i);
            if (value == null || value.isEmpty()) {
                continue;
            }
            sb.append(value);
            if (i + 1 < headerValues.size()) {
                sb.append(",");
            }
        }
        return sb.toString();
    }

    public  HttpHeadersImpl(io.netty.handler.codec.http.HttpHeaders httpHeaders);

}