/**
 * A `setTimeout` that can be paused and resumed.
 *
 * Pausing banks the time that has already elapsed, so resuming fires the
 * callback after the *remaining* time rather than restarting the full delay.
 *
 * Used for the toast auto-dismiss countdown, which pauses while the cursor is
 * over the toast.
 */
export declare class PausableTimeout {
    private readonly _callback;
    /** Time left on the countdown, updated each time it's paused. */
    private _remainingMs;
    private _timerId;
    /** When the currently-running countdown was (re)started. */
    private _startedAt;
    private _isPaused;
    /** Set once the callback has fired (or the countdown was cancelled). */
    private _isDone;
    constructor(callback: () => void, delayMs: number);
    /** Whether the countdown is currently paused. */
    get isPaused(): boolean;
    /** Start the countdown for whatever time is left on it. */
    start(): void;
    /** Pause the countdown, banking the time that has already elapsed. */
    pause(): void;
    /** Resume a paused countdown from where it left off. */
    resume(): void;
    /** Cancel the countdown for good; it can't be started again. */
    cancel(): void;
    private clear;
}