Given a web component extending LitElement:

import { html, LitElement } from 'lit';
import { customElement } from 'lit/decorators.js';

@customElement('my-element')
export class MyElement extends LitElement {
    render() {
        return html`
<div>some static content</div>
<div class="slotted"><slot></slot></div>
<div>more static content</div>
        `;
    }
}

And the component is used like this:

<my-element>${maybeContentMaybeNothing}</my-element>

Since maybeContentMaybeNothing could contain html or text or nothing at all, how can the div.slotted element be hidden if maybeContentMaybeNothing contains nothing, but shown if it contains anything?