/**
 * Copyright (c) Meta Platforms, Inc. and affiliates.
 *
 * This source code is licensed under the MIT license found in the
 * LICENSE file in the root directory of this source tree.
 *
 */
/** @internal */
export declare function normalizeClassNames(...classNames: Array<typeof undefined | boolean | null | string>): Array<string>;
/**
 * Takes an HTML element and adds the classNames passed within an array,
 * ignoring any non-string types. A space can be used to add multiple classes
 * eg. addClassNamesToElement(element, ['element-inner active', true, null])
 * will add both 'element-inner' and 'active' as classes to that element.
 * @param element - The element in which the classes are added
 * @param classNames - An array defining the class names to add to the element
 */
export declare function addClassNamesToElement(element: HTMLElement, ...classNames: Array<typeof undefined | boolean | null | string>): void;
/**
 * Takes an HTML element and removes the classNames passed within an array,
 * ignoring any non-string types. A space can be used to remove multiple classes
 * eg. removeClassNamesFromElement(element, ['active small', true, null])
 * will remove both the 'active' and 'small' classes from that element.
 * @param element - The element in which the classes are removed
 * @param classNames - An array defining the class names to remove from the element
 */
export declare function removeClassNamesFromElement(element: HTMLElement, ...classNames: Array<typeof undefined | boolean | null | string>): void;