/**
 * @license Copyright (c) 2003-2026, CKSource Holding sp. z o.o. All rights reserved.
 * For licensing, see LICENSE.md or https://ckeditor.com/legal/ckeditor-licensing-options
 */
/**
 * @module utils/first
 */
/**
 * Returns first item of the given `iterator`.
 */
export declare function first<T>(iterator: Iterator<T>): T | null;