export declare function sleep(time: number): Promise<unknown>;
export declare function requiredCheck<T>(obj: T, keys: Array<keyof T>): string[];
export declare class Resolver<R = void> {
    promise: Promise<R>;
    resolve: (data: R) => void;
    reject: (e: any) => void;
    constructor();
}
export declare function isNeedReconnectError(err: any): boolean;
export declare function instanceNeedNamespace(instanceId: string): boolean;