/**
 * A deterministic clock for the in-memory reference and the conformance suite.
 *
 * TTL behavior (presence expiry, activity expiry, reservation expiry) is part
 * of the contract, and asserting it against a wall clock means either sleeping
 * or accepting flakes. A composition under test injects one of these and moves
 * time explicitly.
 */
import type { MutableClock } from '../stores';
/** Fixed start instant, so golden-ish assertions in the suite read the same on every run. */
export declare const IN_MEMORY_CLOCK_EPOCH = "2026-01-01T00:00:00.000Z";
export declare function createMutableClock(start?: Date): MutableClock;