import { LightningElement } from '@lwc/engine-core';
/**
 * EXPERIMENTAL: This function is almost identical to document.createElement with the slightly
 * difference that in the options, you can pass the `is` property set to a Constructor instead of
 * just a string value. The intent is to allow the creation of an element controlled by LWC without
 * having to register the element as a custom element.
 *
 * @example
 * ```
 * const el = createElement('x-foo', { is: FooCtor });
 * ```
 */
export declare function createElement(sel: string, options: {
    is: typeof LightningElement;
    mode?: 'open' | 'closed';
}): HTMLElement;