How to use Nginx NJS with native nodejs modules and webpack?

Question

There is a guide https://nginx.org/en/docs/njs/node_modules.html guide that describes how to use 'native' nodejs modules with njs.

I followed the guide until I did not understand what it means in bold:

Note that in this example generated code is not wrapped into function
and we do not need to call it explicitly. The result is in the "dist" directory:

$ cat dist/wp_out.js code.js > njs_dns_bundle.js

Let's call our code at the end of a file: <<<--- HERE

var b = set_buffer(global.dns);
console.log(b);

And execute it using node:

$ node ./njs_dns_bundle_final.js

Question is how do I include / require / import the webpack generated njs_dns_bundle.js in njs_dns_bundle_final.js which is the name of the Let's call our code at the end of a file since without it I get the error:

njs_dns_bundle_final.js:1
var b = set_buffer(global.dns);
ReferenceError: set_buffer is not defined

My code.js:

module.exports = {
   hello: function set_buffer(dnsPacket) {
        // create DNS packet bytes
        var buf = dnsPacket.encode({
            type: 'query',
            id: 1,
            flags: dnsPacket.RECURSION_DESIRED,
            questions: [{
                type: 'A',
                name: 'google.com'
            }]
        })

        return buf;
    }
}

My njs_dns_bundle_final.js:

var myModule = require('./njs_dns_bundle');

var b = myModule.hello(global.dns);
console.log(b);

Node runs fine I think?!:

node ./njs_dns_bundle_final.js
<Buffer 00 01 01 00 00 01 00 00 00 00 00 00 06 67 6f 6f 67 6c 65 03 63 6f 6d 00 00 01 00 01>

NJS does not:

njs ./njs_dns_bundle_final.js
Thrown:
Error: Cannot find module "./njs_dns_bundle"
    at require (native)
    at main (njs_dns_bundle_final.js:1)

Thanks