private ResponseHeaders responseHeaders() {
        final ResponseHeadersBuilder headersBuilder = responseHeadersBuilder(httpStatus(), headers);
        cookies.forEach(c -> c.addHeader(headersBuilder));
        return headersBuilder.build();
    }
Implements {@link org.jboss.resteasy.spi.HttpResponse}.
resteasy/src/main/java/com/linecorp/armeria/server/resteasy/ResteasyHttpResponseImpl.java