/**
 * Copyright 2026 Adobe. All rights reserved.
 * This file is licensed to you under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License. You may obtain a copy
 * of the License at http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software distributed under
 * the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR REPRESENTATIONS
 * OF ANY KIND, either express or implied. See the License for the specific language
 * governing permissions and limitations under the License.
 */
/**
 * Register a dismissible as the topmost entry when it opens. Any existing entry
 * for the same key is removed first, so re-registering moves the key to the top
 * and the stack never holds duplicates.
 */
export declare function registerDismissible(key: object): void;
/**
 * Remove the most-recent entry matching the key when it closes. Idempotent: a
 * key that is not present is a no-op (safe to call from `disconnectedCallback`).
 */
export declare function unregisterDismissible(key: object): void;
/**
 * Whether the key is the topmost (most-recently-registered) dismissible.
 */
export declare function isTopDismissible(key: object): boolean;