/**
 * Returns the target DOM node to append the element to.
 * If the fallbackTargetDOMNode is provided, it will return the fallbackTargetDOMNode.
 * If the fallbackTargetDOMNode is not provided, it will return the body element of the ownerDocument, or automatically create & choose the custom element under ShadowDOM.
 *
 * @param fallbackTargetDOMNode - The fallback target DOM node, if specified, it will return this node.
 *
 * @param hangingElement - The element to detect the rootNode, if not provided, it will return the body element of the ownerDocument, or automatically create & choose the custom element under ShadowDOM.
 *
 * @returns The target DOM node
 */
export declare function getTargetDomNode(fallbackTargetDOMNode?: HTMLElement | null, hangingElement?: HTMLElement | null): HTMLElement;