export type TimerHandle = ReturnType<typeof globalThis.setTimeout> | number;
export interface Clock {
    now(): number;
    setTimeout(fn: () => void, delayMs: number): TimerHandle;
    clearTimeout(handle: TimerHandle): void;
    setInterval(fn: () => void, delayMs: number): TimerHandle;
    clearInterval(handle: TimerHandle): void;
}
export declare class SystemClock implements Clock {
    now(): number;
    setTimeout(fn: () => void, delayMs: number): TimerHandle;
    clearTimeout(handle: TimerHandle): void;
    setInterval(fn: () => void, delayMs: number): TimerHandle;
    clearInterval(handle: TimerHandle): void;
}