/**
 * Return the container. If it's a string, it is considered a
 * css selector and retrieves the first matching element. Otherwise
 * test if it validates that it's a correct DOMElement.
 *
 * @param {string|HTMLElement} selectorOrHTMLElement CSS Selector or container node.
 * @return {HTMLElement} Container node
 * @throws Error when the type is not correct
 */
export declare function getContainerNode(selectorOrHTMLElement: string | HTMLElement): HTMLElement;