public static HttpHeaders toArmeria(io.netty.handler.codec.http.HttpHeaders inHeaders) {
        if (inHeaders.isEmpty()) {
            return HttpHeaders.of();
        }

        final HttpHeadersBuilder out = HttpHeaders.builder();
        out.sizeHint(inHeaders.size());
        toArmeria(inHeaders, out);
        return out.build();
    }
Converts the specified Netty HTTP/1 headers into Armeria HTTP/2 headers.
core/src/main/java/com/linecorp/armeria/internal/common/ArmeriaHttpUtil.java