import { FlushCallback, TransformFunction } from 'through2';
import { Through2ConcurrentOptions } from 'through2-concurrent';
import { TransformTyped } from '../stream.model';
/**
 * Wrapper around `through2-concurrent`.
 * objectMode defaults to true
 */
export declare function transformConcurrent<IN = any>(opt?: Through2ConcurrentOptions, transform?: TransformFunction, flush?: FlushCallback): TransformTyped<IN, IN>;