import type { Action, ExtensionAuto } from "../../../core/index.js";
export { underlineMarkName, underlineType } from "./UnderlineSpecs/index.js";
declare const undAction = "underline";
export type UnderlineOptions = {
    underlineKey?: string | null;
};
export declare const Underline: ExtensionAuto<UnderlineOptions>;
declare global {
    namespace WysiwygEditor {
        interface Actions {
            [undAction]: Action;
        }
    }
}