export declare function isContainingBlock(element: HTMLElement): boolean;
/**
 * Returns an element that is used to position the given element.
 * @see https://developer.mozilla.org/en-US/docs/Web/CSS/Containing_block
 */
export declare function getContainingBlock(startElement: HTMLElement): HTMLElement | null;
export declare function findUpUntilMultiple({
  startElement,
  tests
}: {
  startElement: HTMLElement;
  tests: Record<string, (el: HTMLElement) => boolean>;
}): Record<string, HTMLElement>;
export declare function isNode(target: unknown): target is Node;
export declare function isHTMLElement(target: unknown): target is HTMLElement;
export declare function isSVGElement(target: unknown): target is SVGElement;
export declare function isElement(target: unknown): target is Element;