export interface IQueue {
    length: number;
    push<T>(action: () => Promise<T>): Promise<T>;
    canPush(): boolean;
    clear(error?: Error | string): void;
}
export declare class Queue implements IQueue {
    get length(): number;
    private readonly _actions;
    private readonly _maxLength;
    private _active;
    constructor(maxLength: number);
    push<T>(action: () => Promise<T>): Promise<T>;
    clear(error?: Error | string): void;
    canPush(): boolean;
    private run;
}