export interface Queue {
    queue<T>(f: () => Promise<T>): Promise<T>;
}
export declare class TailHeadQueue implements Queue {
    private queue_list;
    private queue_size;
    private queue_period;
    private allowance;
    private last_end;
    constructor(size: any, period: any);
    _on_settled(): void;
    queue<T>(f: () => Promise<T>): Promise<T>;
}