/**
 * Adds one or more classes to an element's class attribute, excluding classes that already exist, including SVG elements.
 *
 * @param el - The element to add class names to
 * @param classes - One or more classes to add to the element, passing one or multiple class names in each argument
 *
 * @example
 * const el = document.createElement('div')
 * addClass(el, 'new-class-1', 'new-class-2')
 * console.log(el.className)
 *
 * @since 1.0.0
 */
declare const addClass: (el: HTMLElement | SVGElement | null | undefined, ...classes: string[]) => void;
export default addClass;