import { Parent } from './Parent.js';
import type { Widget, WidgetProperties } from '../widgets/Widget.js';
/**
 * A specialised version of the {@link Parent} class for parents with a single
 * mandatory child.
 *
 * @category Widget
 */
export declare abstract class SingleParent<W extends Widget = Widget> extends Parent<W> {
    readonly child: W;
    /**
     * @param child - The mandatory single child of this widget. Cannot be changed later.
     */
    constructor(child: W, properties?: Readonly<WidgetProperties>);
    [Symbol.iterator](): Iterator<W>;
    get childCount(): 1;
}