@api
    modalBody$$(selectors = '') {
        return selectAll(this.template, LIGHTNING_MODAL_BODY, selectors);
    }
Query select multiple elements in lightning-modal-body
Usage:
- `elem.modalBody$$()` Returns all nodes in body
- `elem.modalBody$$('button, [data-button]')` Returns buttons in body
@param {string} selectors Ex: 'div', 'button, [data-button]'
@returns elements[]