/**
 * Sleeps for a given time.
 *
 * @param millis Time in milliseconds
 */
export declare const sleep: (millis: number) => Promise<void>;
/**
 * Checks if the timeout occurred.
 *
 * @param startTimeMillis Start time value in milliseconds
 * @param maxDurationMillis Maximum duration in milliseconds
 */
export declare const checkTimeout: (startTimeMillis: number, maxDurationMillis: number) => boolean;