heading(t, r, a) {
        a = a.toLowerCase().trim().replace(/<[!\/a-z].*?>/gi, "");
        const i = `${n}${I4.slug(a)}`, l = { level: r, text: t, id: i };
        return L4.push(l), `<h${r} id="${i}">${t}</h${r}>
`;
      }
By default, if Prism is in a web worker, it assumes that it is in a worker it created itself, so it uses
`addEventListener` to communicate with its parent instance. However, if you're using Prism manually in your
own worker, you don't want it to do this.

By setting this value to `true`, Prism will not add its own listeners to the worker.

You obviously have to change this value before Prism executes. To do this, you can add an
empty Prism object into the global scope before loading the Prism script like this:

```js
window.Prism = window.Prism || {};
Prism.disableWorkerMessageHandler = true;
// Load Prism's script
```

@default false
@type {boolean}
@memberof Prism
@public