In React, say, I might write

    <MyComponent worker={worker} />

and expect the worker instance to be passed as an object to `MyComponent` as a prop. But with webcomponents, I can't do something like that.

    this.innerHTML = `<my-component worker="${worker}">`

will just stringify the worker and pass that string to the `my-component`. To get the worker instance to be passed correctly, I'd need to do something like

    this.innerHTML = `<my-component>`
    this.firstChild.worker = worker;