/// <reference types="node" />
import { Transform, TransformOptions } from 'stream';
export declare class PromiseTransformStream extends Transform {
    private transform;
    private concurrency;
    results: any;
    resumeCallback: () => void;
    endCallback: () => void;
    private pushIndex;
    private activeCount;
    constructor(transform: (item: any) => Promise<any>, concurrency?: number, options?: TransformOptions);
    _transform(chunk: any, encoding: any, callback: any): void;
    end(chunk: any, encoding?: any, cb?: () => void): void;
}