e of a tracking <code>Map</code> to store the metadata:</p>
<pre><code class="language-js">const { createServer } = require('http');
const {
  executionAsyncId,
  executionAsyncResource,
  createHook
} = require('async_hooks');
const sym = Symbol('state'); // Private symbol to avoid pollution

createHook({
  init(asyncId, type, triggerAsyncId, resource) {
    const cr = executionAsyncResource();
    if (cr) {
      resource[sym] = cr[sym];
    }
  }
}).enable();

const server = createServer((req, res) => {
